The Doorkeeper

For a few seconds nobody spoke at all. It took that long for the sheer lunacy of it to sink in. Then Ron said exactly what Harry was thinking.

‘You’re both mental.’

‘Ridiculous!’ said Hermione faintly.

‘No, wait, wait, wait. Despite the universe trying to make me out to be a mug, I’m not a bloody mug. That’s a rat. Peter Pettigrew’s dead!’ said Harry. ‘He killed him twelve years ago!’

He pointed at Black. Black’s face twitched violently at the words, and Harry saw it.

‘Look at him! He’s guilty and he knows it!’ Harry shouted. He could hardly believe any of this was happening.

‘I meant to,’ Black growled, baring his yellow teeth, ‘but little Peter got the better of me... not this time, though!’

He sprang at Scabbers. Crookshanks went flying to the floor. Black’s whole weight landed on Ron’s broken leg, and Ron howled.

‘Sirius, NO!’ Lupin yelled. He hurled himself forward, seized Black and dragged him off Ron again. ‘WAIT! You can’t do it just like that- they need to understand- we’ve got to explain-’

‘We can explain afterwards!’ Black snarled, struggling to shake Lupin off.

One of his hands was still clawing at the air, reaching for Scabbers. The rat was shrieking like a stuck pig, scratching at Ron’s face and neck in his frenzy to get away.

‘They’ve…got…a…right…to…know…everything!’ Lupin panted. He was hanging on to Black with both arms. ‘Ron’s kept him as a pet! There are parts of it even I don’t understand! And Harry- you owe Harry the truth, Sirius!’

Harry saw something happen to Lupin then, in the moment that he had his face closest to the rat. The tendons stood out in his neck like ropes. His lips peeled back from his teeth. A sound came out of him that was nothing like a man’s voice, a deep, wet snarl, so low that Harry felt it in the floorboards under his trainers. For one dreadful second Lupin’s arms stopped holding Black back and strained forward instead, past him, towards Ron’s cupped hands.

Black felt it too. He stopped struggling at once. He twisted round in Lupin’s grip and caught hold of his friend by both shoulders instead.

‘Moony,’ he said, very low. ‘Moony. Look at me. Not at him. At me.’

Lupin shut his eyes. His chest heaved, once, twice. When he opened them again, they were his own: tired, grey-brown, frightened.

‘I’m all right,’ he said hoarsely. ‘I’m all right, Padfoot.’

Black let go of him slowly. He looked past Lupin at Harry for a long moment. Then his hollow eyes went straight back to Scabbers, who was now pinned tight under Ron’s bitten, scratched, bleeding hands.

‘All right, then,’ said Black. His eyes never left the rat. ‘Tell them whatever you like. But make it quick, Remus. I want to commit the murder I was imprisoned for...’

‘You’re filling me with such confidence in your innocence,’ Harry murmured drily.

Nobody laughed. Harry hadn’t really expected them to. His wand hand wasn’t quite steady, he noticed, so he tucked it under his other arm, where Black couldn’t see it.

‘You’re nutters, both of you,’ said Ron shakily. He looked from Harry to Hermione, hoping for some backup. ‘I’ve had enough of this. I’m off.’

He struggled to get up on his good leg. At once Lupin’s wand came up again, aimed at Scabbers.

‘You’re going to hear me out, Ron,’ he said quietly. ‘Just keep a tight hold on Peter while you listen.’

‘HE’S NOT PETER, HE’S SCABBERS!’ Ron yelled.

He tried to cram the rat back into his pocket. Scabbers fought like a wildcat. Ron lurched, lost his balance and nearly fell. Harry had to catch him and ease him back down on to the bed. For a moment, Ron’s hand closed round Harry’s wrist.

‘Don’t you go near either of them,’ Ron muttered, through gritted teeth. ‘You hear me? Not on your own. I don’t care what they say.’

‘I wasn’t planning to,’ said Harry. ‘I like my head where it is.’

Then, ignoring Black altogether, he turned to Lupin.

‘There were witnesses who saw Pettigrew die,’ he said. ‘A whole street full of them...’

‘They didn’t see what they thought they saw!’ said Black savagely, his eyes still fixed on Scabbers as the rat writhed in Ron’s hands.

‘No, they thought they saw a mutant attack, Bloody Magneto or whoever it is nowadays’ said Harry sarcastically.

‘Everyone thought Sirius killed Peter,’ said Lupin, nodding. ‘I believed it myself- until I saw the map tonight. Because the Marauder’s Map never lies... Peter’s alive. Ron’s holding him, Harry.’

Harry looked down at Ron. Their eyes met. Without a word, they agreed that Black and Lupin had both gone completely round the bend. None of it made any sense. How could Scabbers possibly be anybody at all? Azkaban must have turned Black’s brain to mush after all. Why on earth was Lupin going along with him?

Lupin seemed to see what they were thinking. He turned to Hermione instead.

‘Hermione, you know what I am. So you know I can sense these things. Before I even knew Sirius was innocent I could sense something off about the rat. It’s like a smell for us. The darkness. He smells of dark magic. Of his master. Of the Wyrm! It reeks, it’s vile!’

He meant to hiss the last few words, Harry thought. They came out as another growl instead. It rolled round the dusty room like thunder in a barrel.

Hermione spoke next. Her voice was trembling, though she was trying very hard to keep it calm. A calm voice, she seemed to think, might coax Professor Lupin back to talking sense.

‘But Professor Lupin... Scabbers can’t be Pettigrew... it just can’t be true, you know it can’t...’

‘But I can smell it!’ Lupin shouted.

He took a step towards her. Hermione didn’t back away; she raised her wand instead, very fast, and pointed it at his heart. Harry saw her eyes go bright and hard, as if part of her were hoping he would take one more step.

Lupin stopped. He passed a hand over his face.

‘You... you can’t ever understand what it’s like. And you’re better off for that. B-but, I smell it all around me. From the dementors. From any time a dark spell is cast. And especially from Peter.’

His hand had crept up to his collar. It closed round something there, under his shirt, the way it had in Snape’s office over the map. Harry saw his lips move. He couldn’t hear the words, but he could guess them by now. Deliver us from evil.

It worried Harry more than anything else that had happened so far. Lupin was fighting something, and he was losing.

Hermione hadn’t lowered her wand. She plainly thought the best thing she could do for everybody was to set the facts straight, quickly, before anybody did anything stupid.

‘People would know if Peter Pettigrew had been an Animagus. We did Animagi in class with Professor McGonagall. And I looked them up when I did my homework- the Ministry of Magic keeps tabs on witches and wizards who can become animals; there’s a register showing what animal they become, and their markings and things... and I went and looked Professor McGonagall up on the register, and there have been only seven Animagi this century, and Pettigrew’s name wasn’t on the list-’

Harry was still trying to take in how much extra reading Hermione did, just for fun, when Lupin began to laugh.

‘Right again, Hermione!’ he said. ‘But the Ministry never knew that there used to be three unregistered Animagi running around Hogwarts.’

‘Of course there were,’ said Harry. ‘Why wouldn’t there be? I expect Filch is a Norwegian Ridgeback on his days off.’

‘If you’re going to tell them the story, get a move on, Remus,’ snarled Black. His eyes were still following every twitch the rat made. ‘I’ve waited twelve years, I’m not going to wait much longer.’

‘All right... but you’ll need to help me, Sirius,’ said Lupin. ‘I only know how it began...’

Lupin broke off. Behind him something had creaked loudly. The bedroom door had swung open all on its own.

Every one of them turned to stare at it.

Lupin strode across to it and looked out on to the landing. Harry had thought until then that Black was the more dangerous of the two men in the room. He wasn’t so sure any more. Lupin stood in the doorway with his shoulders hunched up round his ears, his nostrils flared wide, his head turning slowly from side to side. He was growling out into the dark, openly now, without even trying to hide it, and it didn’t sound remotely human.

Then the growl faltered into a puzzled sniff. Lupin frowned. There seemed to be something on the air that he almost knew, but the reek of the rat was swamping everything.

‘No one there...’

‘This place is haunted!’ said Ron.

‘It’s not,’ said Lupin. He was still frowning at the door. ‘The Shrieking Shack was never haunted... The screams and howls the villagers used to hear were made by me.’

‘That,’ said Harry, ‘is actually less comforting than ghosts.’ Lupin brushed the greying hair off his forehead and was silent for a moment, thinking.

‘That’s where all of this starts… with my becoming a Garou. None of this could have happened if I hadn’t been bitten... and if I hadn’t been so foolhardy...’

He looked sober and very tired. Ron opened his mouth to say something.

‘Shh!’ said Hermione. She was watching Lupin with the closest attention, the way she watched a teacher who was about to say something that would be in the exam.

‘I was a very small boy when I received the bite. Garou are normally born naturally, they frown on those with... my circumstances. My parents tried everything, but in those days there was no cure. The potion that Professor Snape has been making for me is a very recent discovery. It makes me safe, you see. As long as I take it, the instincts, the compulsion to transform, to root out and destroy the Wyrm now, this very instant, is suppressed. It never truly goes away. But I can control it.’

He took out his handkerchief and wiped his face with it again.

‘It’s hard. So very hard. Even with the potion. Hogwarts is a magnificent place. But it’s steeped in dark magic as much as light. I’m... my people, are very sensitive to such things.’

Some of the strain had gone out of his shoulders; he seemed to have got a grip on himself again, for the moment at least.

‘Before the Wolfsbane Potion was discovered, however, I was at risk of transforming the moment I sensed anything dark. Anything that smelled of the Wyrm. And when I did, I couldn’t always control myself... It seemed impossible that I would be able to come to Hogwarts. Other parents weren’t likely to want their children exposed to me.’

‘But then Dumbledore became Headmaster, and he was sympathetic. He said that as long as we took certain precautions, there was no reason I shouldn’t come to school...’

Lupin sighed, and looked straight at Harry.

‘I told you, months ago, that the Whomping Willow was planted the year I came to Hogwarts. The truth is that it was planted because I came to Hogwarts. This house,’ Lupin looked miserably round the room, ‘the tunnel that leads to it, they were built for my use. Once a month, on the full moon, when my... condition was always most strong, most hard to resist, I was smuggled out of the castle, into this place, to transform. The tree was placed at the tunnel mouth to stop anyone coming across me while I was dangerous.’

Harry couldn’t see where any of this was going. He was listening hard all the same. Apart from Lupin’s voice, the only sound in the room was Scabbers’s frightened squeaking.

‘My transformations in those days were… were terrible. It is very painful to turn into a Garou. It’s a complete surrender to instincts and madness. All I’d want to do is bite and claw at all the Wyrm-touched things around me. Seeing as there was none of that but myself as a Wizard, in mad rage I’d bite and claw at myself instead. The villagers heard the noise and the screaming and thought they were hearing particularly violent spirits. Dumbledore encouraged the rumour... Even now, when the house has been silent for years, the villagers don’t dare approach it...’

Harry thought of the claw marks downstairs, ripped right through the plaster to the brick a foot above his own head. He had a sudden picture of a boy not much older than himself, shut up alone in this house, tearing at the walls and at his own arms because there was nothing else to tear at. For a moment he couldn’t look at Lupin.

‘But apart from my transformations, I was happier than I had ever been in my life. For the first time ever, I had friends, three great friends. Sirius Black... Peter Pettigrew... and, of course, your father, Harry - James Potter.’

On the bed, Black made a small sound. When Harry glanced at him, he had dropped his eyes from the rat for the first time, and his gaunt face had softened into something that was almost a smile.

‘Now, my three friends could hardly fail to notice that I disappeared once a month. I made up all sorts of stories. I told them my mother was ill, and that I had to go home to see her... I was terrified they would desert me the moment they found out what I was. But of course, they, like you, Hermione, worked out the truth...’

‘James worked it out,’ said Black hoarsely. ‘In the end. I’d have got there first, if I hadn’t been so sure it was a girl.’

‘You did think that,’ said Lupin. ‘For nearly two months. You told the entire common room that it was Rita.’

‘I was thirteen.’

‘You were an idiot.’

‘Yes,’ said Black, and the not-quite smile came back. ‘That too.’

Harry looked from one of them to the other. For a second, in the middle of everything, they sounded exactly like Ron and himself.

‘And they didn’t desert me at all. Instead, they did something for me that would make my transformations not only bearable, but the best times of my life. They became Animagi.’

‘My dad too?’ said Harry, astounded.

‘Yes, indeed,’ said Lupin. ‘It took them the best part of three years to work out how to do it. Your father and Sirius here were the cleverest students in the school, and lucky they were, because the Animagus transformation can go horribly wrong- one reason the Ministry keeps a close watch on those attempting to do it. Peter needed all the help he could get from James and Sirius. Finally, in our fifth year, they managed it. They could each turn into a different animal at will.’

‘But how did that help you? Especially with all those compulsions and instincts,’ said Hermione, sounding puzzled.

‘Ah, you see, Animagus magic isn’t Wyrm-touched at all. It’s very much light magic. Not as close to God as the Patronus. But light magic none the less. In their animal form, my war form would tolerate my friends. In fact, they were often the only thing it ever tolerated. They sneaked out of the castle every month under James’s Invisibility Cloak. They transformed... Peter, as the smallest, could slip beneath the Willow’s attacking branches and touch the knot that freezes it. They would then slip down the tunnel and join me. Under their influence, I became less dangerous. My body was still wolfish, but my mind seemed to become less so while I was with them.’

At the word Peter, Lupin’s eyes had gone to the rat in Ron’s hands. Harry saw them flash once, flat and yellow, like a cat’s in a headlamp. Then they were grey again.

‘Hurry up, Remus,’ snarled Black. He was watching Scabbers again, with a dreadful, starving look on his face.

‘I’m getting there, Sirius, I’m getting there... well, highly exciting possibilities were open to us now that we could all transform. Soon we were leaving the Shrieking Shack and roaming the school grounds and the village by night. Sirius and James transformed into such large animals, they were able to keep a werewolf in check. I doubt whether any Hogwarts students ever found out more about the Hogwarts grounds and Hogsmeade than we did... And that’s how we came to write the Marauder’s Map, and sign it with our nicknames. Sirius is Padfoot. Peter is Wormtail. James was Prongs.’

Moony, Wormtail, Padfoot and Prongs. Harry had read those names a hundred times by wandlight under his bedclothes. It had never once occurred to him that one of them might have been his father.

‘What sort of animal-?’ Harry began.

Hermione cut across him.

‘That was still really dangerous! Running around in the dark with a werewolf! What if you’d given the others the slip, and bitten somebody?’

‘A thought that still haunts me,’ said Lupin heavily. ‘And there were near misses, many of them. We laughed about them afterwards. We were young, thoughtless, carried away with our own cleverness.’

His face clouded over.

‘I sometimes felt guilty about betraying Dumbledore’s trust, of course... he had admitted me to Hogwarts when no other headmaster would have done so, and he had no idea I was breaking the rules he had set down for my own and others’ safety. He never knew I had led three fellow students into becoming Animagi illegally. But I always managed to forget my guilty feelings every time we sat down to plan our next month’s adventure. And I haven’t changed...’

Lupin’s face had gone hard. He sounded disgusted with himself.

‘All this year, I have been battling with myself, not just the wolf inside. But my own conscience. Wondering whether I should tell Dumbledore that Sirius was an Animagus. But I didn’t do it. Why? Because I was too cowardly. It would have meant admitting that I’d betrayed his trust while I was at school, admitting that I’d led others along with me... and Dumbledore’s trust has meant everything to me.’

Harry felt a sudden flash of sympathy. He knew that feeling. It was how he felt about Dumbledore himself, and about Lupin, too. He remembered standing in the entrance hall in the spring, with the Marauder’s Map confiscated and Lupin’s quiet, disappointed voice telling him that it was a poor way to repay his parents. He had felt sick with shame for days. It wasn’t hard to imagine Lupin feeling exactly the same about Dumbledore.

‘He let me into Hogwarts as a boy, and he gave me a job when I have been shunned all my adult life, unable to find paid work because of what I am. And so I convinced myself that Sirius was getting into the school using dark arts he learned from Voldemort, that being an Animagus had nothing to do with it... so, in a way, Snape’s been right about me all along.’

‘Snape?’ said Black harshly. He tore his eyes away from Scabbers at last and looked up at Lupin. ‘What’s Snape got to do with it?’

‘He’s here, Sirius,’ said Lupin heavily. ‘He’s teaching here as well.’

Black said something very rude under his breath. Lupin gave him a reproachful look, the sort Mrs Weasley gave the twins. Black had the grace to look faintly ashamed of himself.

Lupin turned back to Harry, Ron and Hermione.

‘Professor Snape was at school with us. He fought very hard against my appointment to the Defence Against the Dark Arts job. He has been telling Dumbledore all year that I am not to be trusted. He has his reasons... you see, Sirius here played a trick on him which nearly killed him, a trick which involved me-’

Black made a scornful noise.

‘It served him right,’ he sneered. ‘Sneaking around, trying to find out what we were up to... hoping he could get us expelled...’

‘Severus was very interested in where I went every month,’ Lupin told them. ‘We were in the same year, you know, and we, er, didn’t like each other very much. He especially disliked James. Jealous, I think, of James’s talent on the Quidditch field... There were other things too though. More understandable reasons.’

Black tutted at that. Lupin ignored him.

‘Anyway, Snape had seen me crossing the grounds with Madam Pomfrey one evening as she led me towards the Whomping Willow to transform. Sirius thought it would be, er, amusing, to tell Snape all he had to do was prod the knot on the tree trunk with a long stick, and he’d be able to get in after me. Well, of course, Snape tried it; if he’d got as far as this house, he’d have met a fully grown werewolf; but your father, who’d heard what Sirius had done, went after Snape and pulled him back, at great risk to his life... Snape glimpsed me, though, at the end of the tunnel. He was forbidden by Dumbledore to tell anybody, but from that time on he knew what I was...’

Harry thought of Snape leaning on the word hairy in his office, with the map in his hand. So that was what he had meant.

‘So that’s why Snape doesn’t like you,’ said Harry slowly, ‘because he thought you were in on the joke?’

‘Wrong, Potter!’ said a cold, sneering voice from the shadows behind Lupin.

Severus Snape was dragging the Invisibility Cloak off his head. His wand was aimed straight at Lupin.

‘I dislike Lupin because he’s a constant danger to Hogwarts and its students. No matter what half-truths he may tell you!’

He was looking at Lupin with open, undisguised disgust.

Hermione shrieked. Black sprang up off the bed. Harry felt as though he had touched a live wire.

‘Oh good,’ he heard himself say, a little too high. ‘Snape. That’s just what tonight needed.’

Nobody paid him the slightest attention.

Lupin had gone rigid. The moment the Cloak came off, his head had snapped round towards Snape like a hound’s, and Harry saw his nostrils flare wide. All the colour drained out of his face. His eyes went, very fast, to Snape’s left arm, then away again. A low, grinding growl started up somewhere deep in his chest. It got louder. It filled the room. On the bed, Crookshanks flattened his ears and spat.

So that was what Lupin had smelt on the landing, Harry thought dimly. Snape had been standing there under the Cloak the whole time.

‘I found this at the base of the Whomping Willow,’ said Snape. He threw the Cloak to one side, taking care that his wand never wavered from Lupin’s chest. ‘Very useful, Potter, I thank you...’

Snape was slightly out of breath. He was struggling, and failing, to hide how pleased he was.

‘You’re wondering, perhaps, how I knew you were here?’ he said, his eyes glittering. ‘I’ve just been to your office, Lupin. You forgot to take your potion tonight, so I took a gobletful along. And very lucky I did... lucky for me, I mean. Lying on your desk was a certain map. One glance at it told me all I needed to know. I saw you running along this passageway and out of sight.’

‘Severus-’ Lupin began.

His voice came out as a snarl. Snape’s lip curled.

‘Control yourself, Lupin,’ he said softly, ‘or I shall save the dementors a great deal of trouble.’ Then, louder: ‘I’ve told the headmaster again and again that you’re helping your old friend Black into the castle, Lupin, and here’s the proof. Not even I dreamed you would have the nerve to use this old place as your hideout.’

Lupin shut his eyes. Harry saw his hand go to his collar once more and close round whatever was hidden there. His lips moved. His voice, when it came, was almost his own.

‘Severus, you’re making a mistake,’ he said urgently. ‘You haven’t heard everything- I can explain- Sirius is not here to kill Harry-’

‘Two more for Azkaban tonight,’ said Snape. His eyes were gleaming with a kind of fanatical light now. ‘I shall be interested to see how Dumbledore takes this... He was quite convinced you were harmless, you know, Lupin... a tame werewolf. Even Minerva didn’t believe it. She had that silver dagger of hers all ready for you, you know.’

Lupin sighed. All the fight seemed to go out of him at once. He was still standing upright, but he seemed to have sunk an inch or two into the floorboards.

‘You fool,’ he said quietly. ‘Severus, I never meant to harm you, then. I even went and apologised for everything. And for the stupidity of my friends.’

‘And I would’ve accepted it if I knew it was serious,’ said Snape coldly.

‘You called,’ said Black, grinning slyly.

‘Shut up! Shut up!’ shouted Snape. His eyes never left Black for an instant.

‘Is a schoolboy grudge worth putting an innocent man back inside Azkaban?’ asked Lupin. He sounded tired and beaten.

BANG!

Thin cords like snakes burst out of the end of Snape’s wand. They twisted themselves round Lupin’s mouth, his wrists and his ankles. He toppled over and hit the floor, unable to move.

Black roared with rage and lunged at Snape. Snape’s wand swung round to point directly between his eyes.

‘Give me a reason,’ he whispered. ‘Give me a reason to do it, and I swear I will. You failed her! You deserve nothing!’

Black stopped dead.

All the rage drained out of his face. What came into it instead was grief, so naked and so sudden that Harry had to look away. Black didn’t argue. He didn’t say anything at all. He simply stood there with Snape’s wand between his eyes, like a man who had heard the same sentence passed on him every night for twelve years and had long since stopped appealing against it.

Her? Harry thought. Failed who?

On the floor, Lupin was straining against his bonds. The cords had been tied tight, but they were creaking now, as if they were being stretched round something that was growing. Harry could hear his breath hissing in and out through his nose. His bound hands had clenched into fists. The knuckles were swelling, thick and dark.

Harry stood rooted to the spot. He had no idea what to do, or who to believe. This was just like Malfoy all over again, only this time there was far more riding on it. Everything he had thought he knew was being turned upside down. He glanced at the other two. Ron looked every bit as lost as he felt. He was still struggling to keep hold of Scabbers.

Hermione, though, edged a step closer to Snape.

‘Professor Snape- it…it wouldn’t hurt to hear what they’ve got to say, w-would it?’ she said breathlessly.

‘Miss Granger, you are already facing suspension from this school,’ Snape spat. ‘You, Potter, and Weasley are out of bounds, in the company of a convicted murderer and a werewolf. You have no idea of the danger of either man here. For once in your life, hold your tongue.’

Harry’s mind was racing. If Harry stood by and let this happen, the dementors would give Black the Kiss. Wasn’t that exactly what he had told himself he wanted, in the History of Magic classroom, with a bottle of Butterbeer in his hand? Yes. He had wanted it desperately. The angry part of him still wanted it now. It wanted Black to suffer, for his mother and father, for the cupboard, for everything that had been taken from him.

But supposing Black hadn’t done it?

‘But if… if there was a mistake-’ Hermione tried again.

‘KEEP QUIET, YOU STUPID GIRL!’ Snape shouted. All at once he looked quite deranged. ‘DON’T TALK ABOUT WHAT YOU DON’T UNDERSTAND!’

Sparks spat from the tip of his wand. It was still levelled at Black’s face. Hermione shut her mouth.

Ron’s ears had gone scarlet. Harry saw his hand tighten round his wand until it shook, and saw his eyes go from Hermione’s white face to Snape’s, as if he were measuring the distance. Hermione wasn’t looking at Snape’s face. She was gazing at the back of his greasy head with an odd, calm, faraway expression.

‘Vengeance is very sweet,’ Snape breathed at Black. ‘How I hoped I would be the one to catch you...’

‘The joke’s on you again, Severus,’ Black snarled. He nodded sharply towards Ron. ‘As long as this boy brings his rat up to the castle, I’ll come quietly...’

That was when Harry made up his mind about Black.

‘Up to the castle?’ said Snape silkily. ‘I don’t think we need to go that far. All I have to do is call the dementors once we get out of the Willow. They’ll be very pleased to see you, Black... pleased enough to give you a little kiss, I daresay...’

Black’s face, which had been grey before, went the colour of chalk.

‘You- you’ve got to hear me out,’ he croaked. ‘The rat- look at the rat-’

Snape’s eyes had a wild gleam in them that Harry had never seen there before. He seemed to be beyond all reason.

‘Come on, all of you,’ he said.

He snapped his fingers. The trailing ends of Lupin’s cords leapt into his hand.

‘I’ll drag the werewolf. Perhaps the dementors will have a kiss for him too-’

Harry’s feet moved before the rest of him had quite caught up. Three quick strides took him across the room. Then he was standing in the doorway, blocking it. It felt right. He had stood up to Quirrell. He had faced down a basilisk. One greasy Potions master was nothing, compared with those.

‘Get out of the way, Potter, you’re in enough trouble already,’ snarled Snape. ‘If I hadn’t been here to save your skin-’

‘Professor Lupin could have killed me about a hundred times this year,’ Harry said. ‘I’ve been alone with him loads of times, having Defence lessons against the dementors. If he was helping Black, why didn’t he just finish me off then?’

‘Don’t ask me to fathom the way a werewolf’s mind works,’ hissed Snape. ‘Get out of the way, Potter.’

Harry didn’t move. Across the room, the bed creaked. Ron had dragged himself up off it on his one good leg and was swaying there with his wand out, pointing it at Snape’s back.

‘Leave him alone,’ said Ron thickly. ‘He’s not moving. And neither am I.’

Harry took a breath.

‘So, you got rumbled in school. Humiliated. Me too, at that Quidditch match. I thought Dracina Malfoy was having a laugh at my expense because of the dementors. Because of... what she knows about me. But she wasn’t. I know that now. I know things are more complicated than pure spite and wrath. I also know that you’re a bully too, Snape.’

Snape’s lip curled so far that it nearly touched his nose.

‘How very touching,’ he said. ‘The great Harry Potter has learnt something from Lucius Malfoy’s daughter. I do hope you wrote it down, Potter. You so seldom learn anything in my lessons that it would be a pity to lose it.’

Snape had missed the point entirely. Harry felt his face go hot.

‘I’m not saying it to be touching,’ he said. ‘I’m saying you’re about to hand two men to the dementors without listening to a word either of them says. Because of a joke. Twenty years ago.’

‘You will not lecture me, boy.’ Snape’s voice had dropped to a soft, deadly whisper. ‘You know nothing of what happened twenty years ago. You know nothing of anything. You are a vain, spoilt, swaggering little celebrity who has been told since the day he could walk that he is special, and you have never once in your life been made to pay for your arrogance-’

Something went off inside Harry like a firework. Spoilt. The cupboard. The bars on the window. He heard his own voice come out of him, cold, quick, perfectly steady.

‘You lost to my dad at school,’ he said, ‘and you’re still down here in the dark trying to win. You haven’t got anybody, have you? Not one friend in the whole castle. Even the Slytherins only put up with you because you fix their marks.’

Snape’s face went from yellow to a dark, mottled red.

‘SILENCE! I WILL NOT BE SPOKEN TO LIKE THAT!’ Snape shrieked. He looked madder than ever. ‘Like father, like son, Potter! I have just saved your neck; you should be thanking me on bended knee! You would have been well served if he’d killed you! You’d have died like your father, too arrogant to believe you might be mistaken in Black- now get out of the way, or I will make you. GET OUT OF THE WAY, POTTER!’

Harry didn’t stop to think. Snape hadn’t even moved before Harry’s wand was up.

‘Expelliarmus!’ he yelled.

His wasn’t the only voice. There was a bang that shook the door in its frame. Snape flew backwards off his feet and hit the wall with a thud. He crumpled down it to the floorboards. A thin line of blood was trickling from his hairline. He was out cold.

Harry looked round. Ron and Hermione had cast the spell at the very same instant as he had. Snape’s wand went sailing up towards the ceiling and dropped on to the bed beside Crookshanks.

‘You shouldn’t have done that,’ said Black, looking at Harry. ‘You should have left him to me...’

Harry wouldn’t meet his eyes. Part of him still wondered whether he had done the right thing.

‘We attacked a teacher... We attacked a teacher...’ Hermione whimpered, staring at Snape’s limp body with frightened eyes. ‘Oh, we’re going to be in so much trouble-’

Underneath the fright, though, Harry saw something else in her face, and it gave him an odd jolt. Her cheeks were flushed a bright, healthy pink. Her eyes were shining. She was looking at the crumpled heap against the wall with the same deep, private satisfaction she wore when she handed in an essay a foot longer than anybody else’s.

‘Did you see how far he went?’ she whispered. ‘Mine was the strongest. I could feel it.’

‘Yeah,’ said Ron faintly, sinking back on to the bed. He was gazing at her, open-mouthed. ‘Yeah. Nice one, Hermione.’

Lupin was still writhing on the floor. Black knelt beside him and pulled the cords away. Lupin got up, rubbing the raw red marks they had left on his wrists. As he passed Snape’s slumped body, Harry saw him check, breathe in, then turn his face sharply away, the way a man turns from a bad smell.

‘Thank you, Harry,’ he said.

‘I’m still not saying I believe you,’ Harry told him.

‘Then it’s time we offered you some proof,’ said Lupin. ‘You, boy - give me Peter, please. Now.’

Ron hugged Scabbers tighter.

‘Come off it,’ he said weakly. ‘Are you trying to say he broke out of Azkaban just to get his hands on Scabbers? I mean...’ He glanced up at Harry and Hermione, hoping they would back him up. ‘OK, say Pettigrew could turn into a rat- there are millions of rats- how’s he supposed to know which one he’s after if he was locked up in Azkaban?’

‘You know, Sirius, that’s a fair question,’ said Lupin, with a slight frown at Black. ‘How did you find out where he was?’

Black slid a bony, clawed hand inside his robes. He pulled out a crumpled scrap of newspaper, smoothed it flat and held it out for the rest of them to see.

Harry knew it at once: the picture of the Weasleys in Egypt from the Daily Prophet, last summer. There, on Ron’s shoulder, with Ron’s hand resting on his head, was Scabbers.

‘How did you get this?’ Lupin asked Black, thunderstruck.

‘Fudge,’ said Black. ‘When he came to inspect Azkaban last year, he gave me his paper. Normally I just have the Quibbler. Lovegood’s a smart man who knows his nargles. But I just wanted a good crossword. I got the paper and there was Peter, on the front page... on this boy’s shoulder... I knew him at once... how many times had I seen him transform? And the caption said the boy would be going back to Hogwarts... to where Harry was...’

‘My God,’ said Lupin softly. His eyes went from the rat to the newspaper, then back. ‘His front paw...’

‘What about it?’ said Ron defiantly.

‘He’s got a toe missing,’ said Black.

‘Of course,’ Lupin breathed. ‘So simple... so brilliant... he cut it off himself?’

‘Just before he transformed,’ said Black. ‘When I cornered him, he yelled for the whole street to hear that I’d betrayed Lily and James. Then, before I could curse him, he blew apart the street with the wand behind his back, killed everyone within twenty feet of himself- and sped down into the sewer with the other rats...’

‘Didn’t you ever hear, Ron?’ said Lupin. ‘The biggest bit of Peter they found was his finger.’

‘Look, Scabbers probably had a fight with another rat or something! He’s been in my family for ages, right-’

‘Twelve years, in fact,’ said Lupin. ‘Didn’t you ever wonder why he was living so long?’

‘We - we’ve been taking good care of him!’ said Ron.

‘Not looking too good at the moment, though, is he?’ said Lupin. ‘I’d guess he’s been losing weight ever since he heard Sirius was on the loose again...’

‘He’s been scared of that mad cat!’ said Ron. He jerked his chin at Crookshanks, purring away on the bed.

That didn’t fit, though. Harry had just remembered something... Scabbers had been poorly before Crookshanks ever came near him... ever since Egypt... ever since the summer, when Black had got out...

‘This cat isn’t mad,’ said Black hoarsely. He put out a thin hand and rubbed Crookshanks between the ears. ‘He’s the most intelligent cat I’ve ever met. He recognised Peter for what he was right away. And when he met me, he knew I was no dog. It was a while before he trusted me... Finally, I managed to communicate to him what I was after, and he’s been helping me...’

‘What do you mean?’ breathed Hermione.

‘He tried to bring Peter to me, but couldn’t... so he stole the passwords into Gryffindor Tower for me... As I understand it, he took them from a boy’s bedside table...’

‘Ugh... bloody Neville,’ Harry murmured.

His brain felt as though it might burst. It was absurd... and yet...

‘But Peter got wind of what was going on and ran for it...’ croaked Black. ‘This cat- Crookshanks, did you call him?- told me Peter had left blood on the sheets... I supposed he bit himself... Well, faking his own death had worked once...’

The words jolted Harry back to his senses.

‘And why did he fake his death?’ he said furiously. ‘Because he knew you were about to kill him like you killed my parents!’

‘Harry!’ Lupin growled.

It was the voice of a vicious wolf. It made the boards over the windows buzz. Every hair on Harry’s arms stood up on end, and for one second he was more frightened of Lupin than he had ever been of Black.

‘Have some sense. Why would Peter even want to stay a rat for so long?’

‘B-because he...’

Harry stopped. He sighed. A thought had crept into his head, quietly, the way thoughts did in exams when you had stopped trying to have them.

‘Because he had something to hide,’ he said slowly. ‘But why would he not tell anyone he was alive?’

‘You’re getting close, Harry,’ said Lupin.

He sounded every inch the brilliant teacher he was, though the wolf was plainly gnawing at him from the inside.

‘Don’t you see? All this time we’ve thought Sirius betrayed your parents, and Peter tracked him down - but it was the other way around, don’t you see? Peter betrayed your mother and father- Sirius tracked Peter down-’

‘B-but Black was the Secret-Keeper...’ said Harry. He was more confused than ever.

Black turned to him.

‘Harry... I as good as killed them,’ he croaked. ‘I persuaded Lily and James to change to Peter at the last moment, persuaded them to use him as Secret-Keeper instead of me... I’m to blame, I know it... The night they died, I’d arranged to check on Peter, make sure he was still safe, but when I arrived at his hiding place, he’d gone. Yet there was no sign of a struggle. It didn’t feel right. I was scared. I set out for your parents’ house straight away. And when I saw their house, destroyed, and their bodies... I realised what Peter must’ve done... what I’d done... God forgive me. It was all my fault.’

His voice cracked right across. He turned away from them all.

Harry thought he was crying. He had fished the little wooden cross out from the neck of his robes again and was holding it in both hands, pressed against his mouth, murmuring into it. Harry caught only a few of the words. My fault... my fault... my most grievous fault...

It was the same thing he had muttered on the floor, Harry realised, while Harry was hitting him.

Nobody said anything for a long moment. When Lupin spoke at last, his voice had iron in it. Harry had never heard him sound like that.

‘Enough of this,’ he said. ‘There’s one certain way to prove what really happened. Ron, give me that rat.’

‘What are you going to do with him if I give him to you?’ Ron asked tensely.

‘Force him to show himself,’ said Lupin. ‘If he really is a rat, it won’t hurt him.’

Ron hesitated. He looked at Harry. Harry didn’t know what to tell him, so he shrugged, very slightly. At long last, Ron handed the rat over.

Scabbers started squealing and wouldn’t stop. He squirmed in Lupin’s grip, with his little black eyes popping.

‘Ready, Sirius?’ said Lupin.

Black had already snatched up Snape’s wand. He came over to Lupin and the struggling rat. His wet eyes seemed to have caught fire.

‘Together?’ he said quietly.

‘I think so,’ said Lupin. He had the rat gripped in his left fist, his wand ready in his right. ‘On the count of three. One - two - THREE!’

Both wands blazed at once with blue-white light. Scabbers hung in the air, writhing frantically. Ron let out a yell. The rat fell, landing on the floorboards with a soft thump. Then came a second flash, brighter than the first, and...

It was like watching a film of a tree growing, speeded up. A head shot up from the floor. Limbs sprouted out of nowhere. Seconds later a man was crouching on the spot where Scabbers had been, twisting his hands together and cringing. On the bed, Crookshanks was spitting and snarling, with the fur standing up all along his back.

He was a very small man, no taller than Harry. What hair he had was thin and colourless, straggling round a broad bald patch. He had the loose, sagging look of somebody who had once been plump and had shrunk very fast. His skin was a dingy grey, rather like Scabbers’s fur. Something of the rat still hung about his sharp nose and tiny, watery eyes. He was panting. His eyes went round them all, quick and frightened. Harry saw them dart towards the door, then away.

The smell hit Lupin a moment later.

Lupin rocked back on his heels as if somebody had struck him in the face. His wand hand dropped. His head went back, with the cords standing out along his throat. A sound came tearing out of him that Harry knew he would hear in nightmares for years: a howl that was choked off halfway, ground down into a snarl between clenched teeth. There was a sharp crack from his shoulders, then another from his spine, and the seams of his shabby robes split open across his back with a long ripping sound. He was taller. Harry was sure he was taller. His hands had curled into hooks, and the nails at the ends of them were black.

Pettigrew squealed and shrank back against the wall.

Black dropped Snape’s wand on to the bed and caught Lupin by the arm with both hands.

‘Steady, Moony,’ he said, low and fast. ‘Steady. Look at me. “Be ye angry, and sin not.” Remember? Lily had it written up on the wall of that awful flat. You used to read it out to me when I was in a temper.’

Lupin’s face was hardly a face at all for a moment. His jaw was too long. His eyes were yellow from one side to the other.

‘“Let not the sun,”’ he ground out, through teeth that didn’t seem to fit in his mouth any more, ‘“go down... upon your wrath.”’

‘That’s it,’ said Black. ‘That’s the one.’

For three long, dreadful seconds, nobody in the room breathed. Then, slowly, Lupin seemed to fold back down into himself. His shoulders dropped. His hands opened. His face was his own again, grey and wet with sweat. He swayed on his feet like a man at the end of a long race.

Harry had backed up against the bed without knowing it. Hermione had stepped in front of him, wand raised, quite calm. She looked almost pleased to have something to point it at. Ron had a fistful of the back of Harry’s robes.

The words went round in Harry’s head. Be ye angry, and sin not. He had heard them before somewhere, a long time ago, in assembly at St Grogory’s, with Dudley kicking the back of his chair. He hadn’t thought about them since. He didn’t much want to think about them now.

Lupin wiped his face with his handkerchief. His hand was shaking. Then he turned back to the little man against the wall, and when he spoke his voice was perfectly pleasant, as though rats turned into old school friends round him every day of the week.

‘Well, hello, Peter,’ he said. ‘Long time, no see.’

‘S-Sirius... R-Remus...’

Even Pettigrew’s voice was squeaky.

‘My friends... my old friends...’

Black snatched Snape’s wand back off the bed, and his wand arm came up. Lupin grabbed his wrist and shook his head at him. Then he faced Pettigrew again. His voice was light and casual. Only Harry, who was close enough to see, noticed how white his knuckles had gone round his own wand, and how carefully he was breathing through his mouth.

‘We’ve been having a little chat, Peter, about what happened the night Lily and James died. You might have missed the finer points while you were squeaking around down there on the bed-’

‘Remus,’ gasped Pettigrew. Sweat was springing out all over his pasty face. ‘You don’t believe him, do you...? He tried to kill me, Remus...’

‘So we’ve heard,’ said Lupin, rather more coldly. ‘I’d like to clear up one or two little matters with you, Peter, if you’d be so-’

‘He’s come to try and kill me again!’ Pettigrew shrieked all of a sudden, jabbing a finger at Black.

Harry saw that it was his middle finger. Where the first finger should have been, there was only a stump.

‘He killed Lily and James and now he’s going to kill me too... You’ve got to help me, Remus...’

Black stared at him out of those bottomless eyes. His face looked more like a skull than ever.

‘No one’s going to try and kill you until we’ve sorted a few things out,’ said Lupin.

‘Sorted things out?’ squealed Pettigrew. His eyes were darting about wildly again, flicking from the boarded windows to the one door. ‘I knew he’d come after me! I knew he’d be back for me! I’ve been waiting for this for twelve years!’

‘You knew Sirius was going to break out of Azkaban?’ said Lupin, frowning. ‘When nobody has ever done it before?’

‘He’s got dark powers the rest of us can only dream of!’ Pettigrew shouted shrilly. ‘How else did he get out of there? I suppose He-Who-Must-Not-Be-Named taught him a few tricks!’

‘He’d know about tricks,’ Harry muttered. ‘He’s been doing one for twelve years.’

Black began to laugh. It was a horrible, joyless laugh, and it filled the whole room.

‘Voldemort, teach me tricks?’ he said.

Pettigrew cringed as if Black had raised a whip.

‘What, scared to hear your old master’s name?’ said Black. ‘I don’t blame you, Peter. His lot aren’t very happy with you, are they?’

‘Don’t know what you mean, Sirius-’ muttered Pettigrew. He was breathing faster than ever.

Sweat was pouring down his face now. Lupin, a yard away, was breathing through his mouth.

‘You haven’t been hiding from me for twelve years,’ said Black. ‘You’ve been hiding from Voldemort’s old supporters. I heard things in Azkaban, Bella was in the next cell over from mine. Peter... They all think you’re dead, or you’d have to answer to them... I’ve heard them screaming all sorts of things in their sleep. Sounds like they think the double-crosser double-crossed them. Voldemort went to the Potters’ on your information... and Voldemort met his downfall there. And not all Voldemort’s supporters ended up in Azkaban, did they? There are still plenty out here, biding their time, pretending they’ve seen the error of their ways... If they ever got wind that you were still alive, Peter-’

‘Don’t know... what you’re talking about...’ Pettigrew repeated, his voice climbing higher still.

He mopped his face on his sleeve, gazing up at Lupin.

‘You don’t believe this- this madness, Remus-’

‘I must admit, Peter, I have difficulty in understanding why an innocent man would want to spend twelve years as a rat,’ said Lupin evenly.

‘Innocent, but scared!’ squealed Pettigrew. ‘If Voldemort’s supporters were after me, it was because I put one of their best men in Azkaban- the spy, Sirius Black!’

Black’s face twisted.

‘How dare you,’ he growled. Suddenly his voice was the deep snarl of the huge black dog. ‘I, a spy for Voldemort? When did I ever sneak around people who were stronger and more powerful than myself? But you, Peter- I’ll never understand why I didn’t see you were the spy from the start. You always liked big friends who’d look after you, didn’t you? It used to be us... me and Remus... and James...’

Pettigrew mopped his face once more. He was gasping.

‘Me, a spy... must be out of your mind... never... don’t know how you can say such a-’

Somewhere far off, down in the dark village at the foot of the hill, a cock crowed.

It was a thin, lonely sound. It came in through the gaps in the boarded windows quite clearly, once, and was gone. Harry thought, vaguely, that it was a funny time of night for a cockerel to be up.

Nobody said anything about it. But Black had stopped moving, and his hand had gone to the little wooden cross at his chest. Lupin’s eyes had closed, just for a moment, like a man hearing his name spoken in a crowd. Pettigrew didn’t seem to have heard it at all.

‘Lily and James only made you Secret-Keeper because I suggested it,’ Black hissed. He said it with such venom that Pettigrew took a step backwards. ‘I thought it was the perfect plan... a bluff... Voldemort would be sure to come after me, would never dream they’d use a weak, talentless thing like you... It must have been the finest moment of your miserable life, telling Voldemort you could hand him the Potters.’

Pettigrew was muttering to himself. Harry caught the odd word, ‘far-fetched’ and ‘lunacy’, but he was watching Pettigrew’s face, which had gone the colour of ash. The man’s eyes kept sliding towards the windows, then the door.

‘Professor Lupin?’ said Hermione timidly. ‘Can- can I say something?’

‘Certainly, Hermione,’ said Lupin courteously.

‘Well- Scabbers- I mean, this- this man- he’s been sleeping in Harry’s dormitory for three years. If he’s working for You-Know-Who, how come he never tried to hurt Harry before now?’

It was a perfectly sensible question. She asked it in a perfectly sensible voice. Her eyes, though, never left Pettigrew’s face, and they were not sensible at all. Harry had the oddest idea that she was memorising it.

‘There!’ squealed Pettigrew, waving his maimed hand in Hermione’s direction. ‘Thank you! You see, Remus? I have never hurt a hair of Harry’s head! Why should I?’

‘I’ll tell you why,’ said Black. ‘Because you never did anything for anyone unless you could see what was in it for you. Voldemort’s been in hiding for twelve years, they say he’s half dead. You weren’t about to commit murder right under Albus Dumbledore’s nose, for a wreck of a wizard who’d lost all of his power, were you? You’d want to be quite sure he was the biggest bully in the playground before you went back to him, wouldn’t you? Why else did you find a wizard family to take you in? Keeping an ear out for news, weren’t you, Peter? Just in case your old protector regained strength, and it was safe to rejoin him...’

Pettigrew’s mouth opened and closed like a goldfish’s. No sound came out.

‘Er- Mr Black- Sirius?’ said Hermione.

Black gave a start at being called that. He gazed at Hermione as if she were some rare and astonishing creature.

‘If you don’t mind me asking, how- how did you get out of Azkaban, if you didn’t use Dark Magic?’

‘Thank you!’ gasped Pettigrew, nodding at her frantically. ‘Exactly! Precisely what I-’

One look from Lupin shut him up.

Black was frowning a little, though not crossly. He seemed to be wondering how to answer. Then he drew out the little cross on its dirty string once more and held it up in the moonlight. For the first time, Harry saw it properly: two splinters of grey wood, bound together crosswise with a twist of thread pulled from a blanket, worn smooth and dark at the centre where a thumb had rubbed it for years.

‘I... I never used to believe in it. God... and all that. That was all Lily. She was... it was her mum, Susan. Lovely woman, made sure her kids were godly.’

He chuckled at that, softly.

‘Remus went to Him first. After Lily and James got married. I was too busy putting out the fires from Bella to notice. But then... then James started going on about all that too. Christ and God. Muggle rubbish, I thought. Peter over here. He started too. Not that I think he was ever truly faithful.’

Pettigrew made a small, protesting squeak. Nobody looked at him.

‘True faith...’ said Harry slowly.

He was remembering the Defence lesson about vampires, back in the autumn, when Lupin’s voice had gone quiet and serious for a moment. A cross in a coward’s hand is a stick of wood. In the hand of somebody who believes...

‘It was in Azkaban. I had nothing else, Harry. Not a single happy memory. But I remembered all the things Lily used to say to me... eventually I had nothing else to lose. So I...’

Black trailed off. He looked embarrassed. Harry knew that sort of embarrassment. He had felt it himself, in a ghost’s company, by a window in the kitchen corridor.

‘You just started believing. Just like that?’ Harry said.

It came out curious instead of sarcastic, which annoyed him.

Black nodded.

‘I knew I was innocent. But that wasn’t enough. The dementors don’t care. They suck everything up anyway. It took me some time. But that was all I had really. I held on to that cross like a life raft and you know what, Harry?’

Harry waited.

‘It didn’t do a thing.’ Black giggled, madly, the way he had giggled on the floor. ‘Not at first. Not until I started believing it. It was the bloody Quibbler. They’d put these mad old Bible passages in there. It was all I had. Amongst those godless, miserable people. Murderers. I’d rather be a doorkeeper in the house of my God, than dwell in the tents of wickedness. And then knowing that, they stopped coming. The dementors. It was like...’

‘They’re repulsed by True Faith, Sirius,’ said Lupin helpfully, in the voice he used in lessons. He had his own hand at his collar again.

‘Yes. I started properly believing. It was all I had for so long.’

Black seemed close to tears. He swallowed hard.

‘That was later, though,’ he said. ‘Much later. At the start, there was nothing like that.’

‘I think the only reason I never lost my mind is that I knew I was innocent. That wasn’t a happy thought, so the dementors couldn’t suck it out of me... but it kept me sane and knowing who I am... helped me keep my powers... so when it all became... too much... I could transform in my cell... become a dog. Dementors can’t see, you know...’

He swallowed again.

‘They feel their way towards people by feeding off their emotions... They could tell that my feelings were less- less human, less complex when I was a dog... but they thought, of course, that I was losing my mind like everyone else in there, so it didn’t trouble them. But I was weak, very weak, and I had no hope of driving them away from me without a wand...

‘But then I saw Peter in that picture... I realised he was at Hogwarts with Harry... perfectly positioned to act, if one hint reached his ears that the Dark Side was gathering strength again...’

Pettigrew kept shaking his head, his lips moving without a sound. He couldn’t take his eyes off Black, like a rabbit in front of a snake.

‘... ready to strike at the moment he could be sure of allies... and to deliver the last Potter to them. If he gave them Harry, who’d dare say he’d betrayed Lord Voldemort? He’d be welcomed back with honours...

‘So you see, I had to do something. I was the only one who knew Peter was still alive...’

Harry remembered what he had overheard outside the parlour door at the Leaky Cauldron last summer, in Mr Weasley’s worried voice. The guards say he’s been talking in his sleep... always the same words... ‘He’s at Hogwarts.’

‘It was as if someone had lit a fire in my head, and the dementors couldn’t destroy it... It wasn’t a happy feeling... it was an obsession... but it gave me strength, it cleared my mind. So, one night when they opened my door to bring food, I prayed and then slipped past them as a dog... It’s so much harder for them to sense animal emotions that they were confused... I was thin, very thin... thin enough to slip through the bars... I swam as a dog back to the mainland... I journeyed north and slipped into the Hogwarts grounds as a dog. I’ve been living in the forest ever since, except when I came to watch the Quidditch, of course. You fly as well as your father did, Harry...’

He looked at Harry. Harry didn’t look away.

‘Believe me,’ croaked Black. ‘Believe me, Harry. I never betrayed James and Lily. I would have died before I betrayed them.’

The little cross was still in his hand. Harry looked at it, and then at the face above it. He had been brave enough, once already this year, to believe Dracina Malfoy when everything in him had told him not to. He thought, for some reason, of how light he had felt afterwards.

At long last, Harry nodded.

‘No!’

Pettigrew had sunk on to his knees, as if Harry’s nod were a sentence of death. He came shuffling forward on them, with his hands pressed together under his chin like a child saying its prayers.

‘Sirius- it’s me... it’s Peter... your friend... you wouldn’t...’

Black lashed out with his foot. Pettigrew shrank away.

‘There’s enough filth on my robes without you touching them,’ said Black.

‘Remus!’ squeaked Pettigrew, turning to Lupin instead and writhing pleadingly in front of him. ‘You don’t believe this... wouldn’t Sirius have told you they’d changed the plan?’

Lupin took a step back from him. It was a very small step, but Harry saw the effort it cost him. His jaw was clenched so hard that a muscle jumped in his cheek.

‘Not if he thought I was the spy, Peter,’ said Lupin. Then, casually, over the top of Pettigrew’s head: ‘I assume that’s why you didn’t tell me, Sirius?’

‘Forgive me, Remus,’ said Black.

‘Not at all, Padfoot, old friend,’ said Lupin. He was rolling up his sleeves. ‘And will you, in turn, forgive me for believing you were the spy?’

‘Of course,’ said Black.

For a moment the two of them simply looked at each other, across twelve years and a kneeling man. Harry had the strangest feeling that he was watching something private, like the end of a long prayer. Then the ghost of a grin flickered across Black’s gaunt face. He began rolling up his sleeves as well.

‘Shall we kill him together?’

‘Yes, I think so,’ said Lupin grimly.

‘You wouldn’t... you won’t...’ gasped Pettigrew.

He scrabbled round on his knees towards Ron.

‘Ron... haven’t I been a good friend... a good pet? You won’t let them kill me, Ron, will you... you’re on my side, aren’t you?’

Ron’s lip had curled. He looked at Pettigrew as if he had found him in his cornflakes.

‘Be glad my Mum hasn’t found out a mad man who transformed into a rat slept in my bed with me. But trust me, she’s going to know soon.’

‘Kind boy... kind master...’ Pettigrew crawled towards Ron. ‘You won’t let them do it... I was your rat... I was a good pet...’

‘If you made a better rat than a human, it’s not much to boast about, Peter,’ said Black harshly.

Ron, white with pain, hauled his broken leg away before Pettigrew could touch it. Pettigrew swung round, still on his knees, and lunged for Hermione instead, catching the hem of her robes.

‘Sweet girl... clever girl... you - you won’t let them... Help me...’

Hermione tugged her robes free of his grasping fingers and stepped back until she was pressed against the wall.

She didn’t look frightened any more. She looked at the creature on the floor with a cold, bright, perfectly steady interest. Harry saw her lips move, very slightly. She was going over something in her head, in order, so as not to forget any of it. It occurred to him, with a small cold shock, that she was planning exactly how she would do it, if she got the chance. He caught a whisper. ‘Not Harry,’ she was breathing. ‘You don’t ever get to touch Harry.’ This was the thing that had slept in Harry’s dormitory for three years. It had helped to kill Harry’s parents.

Pettigrew knelt there, trembling all over. Slowly, he turned his head towards Harry.

‘Harry... Harry... you look just like your father... just like him...’

‘HOW DARE YOU SPEAK TO HARRY?’ roared Black. ‘HOW DARE YOU FACE HIM? HOW DARE YOU TALK ABOUT JAMES IN FRONT OF HIM?’

‘Harry,’ whispered Pettigrew, shuffling towards him with his hands held out. ‘Harry, James wouldn’t have wanted me killed... James would have understood, Harry... he would have shown me mercy...’

Black and Lupin moved as one. They took Pettigrew by the shoulders and flung him down on his back. He lay there quivering with fright, goggling up at the two of them.

The moment Lupin’s hands touched him, the wolf came up again. Harry saw it. Lupin’s fingers sank into Pettigrew’s shoulders far deeper than any man’s fingers should, and a growl ripped out of him so savagely that Pettigrew screamed. Black’s hand closed over Lupin’s wrist. He didn’t say anything this time. He simply held on, until the fingers opened and Lupin stepped back, shuddering from head to foot.

‘You sold Lily and James to Voldemort,’ said Black. He was shaking too. ‘Do you deny it?’

Pettigrew began to sob. It was a horrible thing to see: he looked like some huge, bald, overgrown baby, snivelling on the floorboards.

‘Sirius, Sirius, what could I have done? The Dark Lord... you have no idea... he has dark magic you can’t imagine... I was scared, Sirius, I was never brave like you and Remus and James. I never meant it to happen... He-Who-Must-Not-Be-Named forced me-’

‘DON’T LIE!’ bellowed Black. ‘YOU’D BEEN PASSING INFORMATION TO HIM FOR A YEAR BEFORE LILY AND JAMES DIED! YOU WERE HIS SPY!’

‘He- he was taking over everywhere!’ gasped Pettigrew. ‘Wh-what was there to be gained by refusing him?’

‘What was there to be gained by fighting the most evil wizard who has ever existed?’ said Black, with a terrible fury in his face. ‘Only innocent lives, Peter!’

‘You don’t understand!’ whined Pettigrew. ‘He would have killed me, Sirius!’

‘THEN YOU SHOULD HAVE DIED!’ roared Black. ‘DIED RATHER THAN BETRAY YOUR FRIENDS, AS WE WOULD HAVE DONE FOR YOU!’

Black and Lupin stood side by side, their wands lifted.

‘You should have realised,’ said Lupin quietly, ‘if Voldemort didn’t kill you, we would. Goodbye, Peter.’

Hermione hid her face in her hands and turned away.

For one long moment, Harry wanted it.

It came up in him exactly as it had come up an hour ago, on the floor, with his knuckles bleeding: the hot, roaring, red thing that wanted Pettigrew dead and didn’t care how. This was the one who had really done it. This was the one who had squeaked his parents’ names into Voldemort’s ear. Harry wanted to watch it happen. He wanted to help.

Then, quite clearly, as though somebody had said it aloud next to him, he heard Black’s voice again. Be ye angry, and sin not. He saw the little cross, swinging at Black’s throat on its filthy string, catching the moonlight.

‘NO!’ Harry yelled.

He darted forward, putting himself between Pettigrew and the wands.

‘You can’t kill him,’ he said breathlessly. ‘You can’t.’

Black and Lupin stared at him, astounded.

‘Harry, this piece of vermin is the reason you have no parents,’ Black snarled. ‘This cringing bit of filth would have seen you die too, without turning a hair. You heard him. His own stinking skin meant more to him than your whole family.’

‘I know,’ Harry panted.

He did know. That was the trouble. Black had given in to it once, twelve years ago, chasing Pettigrew into a street full of Muggles. Snape was still giving in to it, twenty years on. There was something else, too, colder and cleverer, underneath. If Pettigrew died in this room, there would be nothing left to show anybody. It would be Black’s word against a corpse.

‘We’ll take him up to the castle. We’ll hand him over to the dementors... He can go to Azkaban... but don’t kill him.’

‘Harry!’ gasped Pettigrew. He flung his arms round Harry’s knees. ‘You- thank you- it’s more than I deserve- thank you-’

‘Get off me,’ Harry spat. He threw Pettigrew’s hands off in disgust. ‘I’m not doing this for you. I’m doing it because Lupin and Bl...Sirius need some evidence of you to acquit him. By the way... did they even give you a trial?’ he asked Sirius.

Black shook his head.

Harry sighed. Twelve years in Azkaban, without so much as a trial. Not one person in all that time seemed to have minded. The wizarding world, Harry thought, needed incredible change.

Nobody stirred. The only sound was Pettigrew, wheezing as he clutched at his chest. Black and Lupin exchanged a long look. Then, together, their wands came down.

‘You’re the only person who has the right to decide, Harry,’ said Black. ‘But think... think what he did...’

‘He can go to Azkaban,’ Harry repeated. ‘If anyone deserves that place, he does...’

Behind him, Pettigrew went on wheezing.

‘Very well,’ said Lupin. ‘Stand aside, Harry.’

Harry hesitated.

‘I’m going to tie him up,’ said Lupin. ‘That’s all, I swear.’

Harry moved aside. This time the cords came from Lupin’s wand. A moment later Pettigrew lay squirming on the boards, tied up and gagged.

‘But if you transform, Peter,’ growled Black, with Snape’s wand trained on Pettigrew as well, ‘we will kill you. You agree, Harry?’

Harry looked down at the wretched little man at his feet. He nodded, making sure that Pettigrew saw him do it.

‘Oh, he won’t get far if he tries,’ said Hermione brightly.

Everybody turned to look at her. She had taken her hands away from her face, and her eyes were shining.

‘I mean it,’ she said. ‘I know at least four spells that would kill a man, and slowly, too. There’s the Entrail-Expelling Curse, of course, but that’s very messy, and over far too quickly to be much use.’

Pettigrew made a faint gurgling noise behind his gag. Hermione didn’t seem to hear it.

‘There’s a fifteenth-century one in a footnote in Moste Potente Potions, the book I got out of the Restricted Section for the Polyjuice. It boils the blood, starting at the feet. The footnote says a Muggle-baiter in Shropshire took nine hours to die of it, and he was awake for every one of them.’

Black’s mouth had fallen slightly open. Lupin had shut his eyes, the way teachers did when they were counting to ten. Hermione was warming to her subject.

‘Then there’s the Desiccation Hex. That one draws all the water out through the skin, very gradually, so the victim shrivels up like a prune. The tongue goes first, which is clever, actually, because it means he can’t scream. If he were a rat at the time, it would be even quicker, wouldn’t it? Rats are so small. I worked out the timings once, just in case. It’s all a matter of body weight. The fourth one is the really interesting one, because it was banned in 1612, so hardly anybody knows the countercurse. You start by-’

‘Thank you, Hermione,’ said Lupin politely, opening his eyes. ‘That is... extremely thorough. I’m quite sure Peter has taken the point. Perhaps we might save the rest of it for another time? Ideally,’ he added, ‘a long time from now, and after your O.W.L.s.’

Hermione blinked. She looked round at them all: at Pettigrew, who had gone the colour of old porridge; at Black; at Harry.

‘What?’ she said.

Ron was looking at her too. He had gone quite white. Then, slowly, his ears began to turn pink. The rest of his face followed. He went on looking at her as if he had never seen anybody quite like her in his life.

‘Remind me,’ he said faintly, going pinker still, ‘never to forget your birthday.’

‘I like her,’ said Black hoarsely to Harry. A slightly unhinged grin had appeared on his face. ‘Lily would have liked her.’

‘Everybody likes her,’ said Harry, ‘until she gets to the footnotes.’

Lupin cleared his throat. All at once he was businesslike.

‘Right,’ he said. ‘Ron, I can’t mend bones nearly as well as Madam Pomfrey, so I think it’s best if we just strap your leg up until we can get you to the hospital wing.’

He crossed to Ron, crouched down and touched his wand to Ron’s leg.

‘Ferula.’

Bandages spun up Ron’s leg and strapped it tight to a splint. Lupin hauled him upright. Ron tested the leg, very cautiously, and found that it held.

‘That’s better,’ he said. ‘Thanks.’

‘What about Professor Snape?’ asked Hermione, in a very small voice, looking down at his crumpled figure.

Harry thought it was quite remarkable, how small her voice could get, when it had just been describing a man drying up like a prune.

‘There’s nothing seriously wrong with him,’ said Lupin. He bent over Snape and felt for his pulse. As he did so, Harry saw him turn his face sharply away from Snape’s left arm, holding his breath, the way he had with Pettigrew. ‘You were just a little- overenthusiastic. Still out cold. Er- perhaps it will be best if we don’t revive him until we’re safely back in the castle. We can take him like this...’

He muttered, ‘Mobilicorpus.’

Snape was jerked upright, as though invisible strings had been tied to his wrists, his neck and his knees. His head still lolled horribly, like a dreadful puppet’s. He dangled a few inches above the floor, with his feet hanging limp.

‘Can we keep him like that?’ said Harry.

Nobody answered. Black’s mouth twitched, though.

Lupin gathered up the Invisibility Cloak and stowed it safely inside his robes.

‘And two of us should be chained to this,’ said Black, prodding Pettigrew with his foot. ‘Just to make sure.’

‘I’ll do it,’ said Lupin.

‘And me,’ said Ron savagely, limping forward.

He made sure, Harry noticed, that he took the side nearest Harry, so that Pettigrew would be on the far side of him from Harry all the way back.

Black conjured heavy manacles out of thin air. Before long Pettigrew was standing again, shackled by one wrist to Lupin and by the other to Ron. Ron’s jaw was clenched. He seemed to regard the truth about Scabbers as a personal insult.

Lupin’s face was set too, but in a different way. Harry could see the sweat standing out on his forehead again. The chain between his wrist and Pettigrew’s was trembling very slightly, the way a lead trembles when a big dog is straining at the other end of it. His free hand had gone to his collar.

Black fell in close behind him.

‘I’m here, Moony,’ he murmured. ‘I’m right here.’

Crookshanks sprang down from the bed. He trotted out of the room ahead of them all, with his bushy ginger tail held high like a flag.