Before any of them could do anything, before any of them could raise their wands, Sirius Black pointed Ron's at them.
'Expelliarmus!' he croaked.
Gwen, Harry and Hermione's wands shout out of their hands, high in the air, and Black caught them. Then he took a step closer. His eyes were fixed on Harry.
'I thought you'd come and help your friend,' he said hoarsely. His voice sounded as though he had long ago lost the habit of using it. 'Your father would have done the same for me. Brave of you not to run for a teacher. I'm grateful... it will make everything much easier...'
Harry started toward Black, but Gwen, Hermione and Ron seized him. Gwen stepped in front of him, blocking Black's view as best she could-- if they could shield him--
'If you want to kill Harry, you'll have to kill us too,' Ron said fiercely, though the effort of standing up had drained him of colour, and he swayed slightly as he spoke.
Something flickered in Black's shadowed eyes.
'Lie down,' he said quietly to Ron. 'You will damage that leg even more.'
'Did you hear me?' Ron said weakly. 'You'll have to kill all four of us!'
'There'll only be one murder here tonight,' said Black, and his grin widened.
'Why's that?' Harry spat, almost knocking Gwen down as he tried to wrench himself free of Ron and Hermione's grip. 'Didn't care last time, did you? Didn't mind slaughtering all those Muggles to get at Pettigrew, your own fiancée? What's the matter, gone soft in Azkaban?'
'Harry!' Hermione whimpered. 'Be quiet!'
'HE KILLED MY MUM AND DAD!' Harry roared, and he broke free of Hermione and Ron's grip, shoved Gwen out of the way and launched himself forward--
Black didn't raise the wands in time. One of Harry's hand fastened over Black's wasted wrist, forcing the wand tips away; Harry's other fist collided with the side of Black's head and they fell backwards into the wall--
Gwen and Hermione was screaming; Ron was yelling; there was a blinding flash as the wands in Black's hand sent a jet of sparks into the air-- Gwen launched forward, ducking as more sparks flew from the wand, trying to grab Black's writhing hand under Harry's grip--
Black's free hand had found Harry's throat-- Harry choked--
Hermione's foot swung forward. Black let go of Harry with a grunt of pain. Gwen fought the wands from Black's grip-- there was a faint clatter--
Ron had managed to throw himself forward, and was now on top of Black-- there was a clatter of the wands dropping, Gwen scrambled for her own--
Harry had fought himself free of the tangle of bodies, ran after his wand rolling across the floor--
Something bushy jumped on top of Gwen's back, claws digging into her, then leapt off again--
Crookshanks planted himself in Harry's chest-- Harry threw him off--
'GET OUT THE WAY!' he yelled to the other three.
Gwen scrambled back to Ron and Hermione, handing them their wands, the warm dripping of blood coming down her face and matting her hair.. Hermione's lip was bleeding, and Ron crawled to the four poster bed, collapsing on it, his white face now tinged with green, both hands clutching his broken leg.
Black was sprawled at the bottom of the wall. His thin chest rose and fell rapidly as he watched Harry walking nearer, his wand pointing straight at Black's heart.
'Going to kill me, Harry?' he whispered.
Gwen, Ron and Hermione watched, still as they could, as Harry stopped right before him. A livid bruise was now forming on Black's head, and his nose was bleeding.
'You killed my parents,' said Harry, his voice shaking slightly, but his wand was quite steady.
Black stared up at him out of those sunken eyes. 'I don't deny it,' he said, very quietly. The shack creaked around them. 'But if only you knew the whole story--'
'The whole story?' Harry repeated. 'You sold them to Voldemort, that's all I need to know!'
'You've got to listen to me,' Black said, his voice urgent. 'You'll regret it if you don't... you don't understand...'
'I understand a lot better than you think,' said Harry, his voice trembling. 'You never heard her, did you? My mum... trying to stop Voldemort killing me... and you did that... you did it...'
Gwen wanted to pull Harry back, stop him from becoming a murderer, no better than Black-- he'd spend his life in Azkaban if he did this-- but before anyone could say another word, Crookshanks streaked across the room and planted himself on Black's chest, right over Black's heart. Black blinked and looked down at the cat. Beside Gwen, Hermione flinched.
'Get off,' Black murmured, trying to push Crookshanks off him, but Crookshanks sank his claws into Black's robes and wouldn't shift. He turned his ugly, squashed face to Harry, and looked up at him with his great yellow eyes. Hermione let out a dry sob.
Harry stared at Black and Crookshanks, his knuckles going white around his wand. The seconds lengthened, and Harry stood frozen, his wand poised, Black staring up at him, Crookshanks on his chest. Ron's ragged breathing came from beside Gwen; Hermione was quite silent; Gwen stayed still, terrified for what would happen next...
Then came a new sound--
Muffled footsteps were echoing up through the floor-- someone was moving downstairs.
'WE'RE UP HERE!' Hermione screamed suddenly. 'WE'RE UP HERE-- SIRIUS BLACK-- QUICK--!'
Black started, almost dislodging Crookshanks; still, Harry stood, his wand almost shaking in his hand.
The door of the room burst open in a shower of red sparks and Professor Lupin came hurtling into the room, his face bloodless, wand raised at the ready. His eyes flickered over Ron, lying on the bed, over Gwen, bleeding and cowering in front of the bed, over Hermione, trembling beside Gwen, to Harry, standing there with his wand covering Black, and then to Black himself, crumpled and bleeding at Harry's feet.
'Expelliarmus!' Lupin shouted.
Gwen's wand flew once more out of her hand, as did Harry's, Hermione's and Ron's, and Lupin caught them all deftly, moving into the room. He stared at Black, who still had Crookshanks lying across his chest. Harry stared at their teacher, his face empty.
Then Lupin spoke, his voice shaking.
'Where is he, Sirius?'
Gwen looked quickly at Lupin. What was he talking about? Who did he mean? Her eyes flicked back to Black, whose face was expressionless. He didn't move for a second. Then, very slowly, he raised his hand and pointed directly at Ron. Gwen spun her head around, bewildered, to look at Ron, who mirrored her expression.
'But then...' Lupin muttered, staring so intently at Black it seemed he was trying to read his mind, 'why hasn't he shown himself before now? Unless--' Lupin suddenly turned to Ron, his eyes wide as though he were seeing something none of the rest could see, '-- unless he was the one... unless you switched... without telling me?'
Very slowly, his sunken eyes never leaving Lupin's face, Black nodded.
'Professor Lupin,' Harry said loudly, 'what's going--?'
But he never finished the question. Lupin had lowered his wand, and Gwen's heart reached her throat. She watched, horrified, as he walked to Black's side, seized his hand, pulled him to his feet so that Crookshanks fell to the floor, and embraced him like a brother.
Gwen's breath caught in her throat, she felt like she was being strangled. Her hair was changing colour rapidly, it couldn't determine which emotion was more prevalent; shock, betrayal, fear, fury-- she was on her feet, her body aching, eyes wild.
'I TRUSTED YOU!' she screamed.
Lupin let go of Black and turned to her.
'You-- you--!'
'Gwen--'
'--you and him!'
'Gwen, calm down--'
'I trusted you!' she shrieked. 'I covered up for you, we didn't tell anyone!'
Hermione was also on her feet, going through the same wild revelation as Gwen. She gripped Gwen's outstretched arm, her mouth and eyes wide.
'Gwen, listen to me, please!' Lupin shouted. 'I can explain--'
Harry was shaking. 'All this time, you've been his friend!' he shouted.
'You're wrong,' said Lupin. 'I haven't been Sirius' friend for twelve years, but I am now... let me explain...'
'NO!' Hermione screamed. 'Harry, don't trust him, he's been helping Black get into the castle, he wants you dead too-- he's a werewolf!'
There was a ringing silence. Everyone's eyes were now on Lupin, who looked remarkably calm, though rather pale.
'Not at all up to your usual standard, Hermione,' he said, 'Only one out of three, I'm afraid. I have not been helping Sirius get into the castle, and I certainly don't want Harry dead...' He shivered. 'But I won't deny that I am a werewolf.'
Ron made a valiant effort to get up again, but fell back with a whimper of pain. Lupin made towards him, looking concerned, but Ron gasped, 'Get away from me werewolf!'
Lupin stopped dead. Then with an obvious effort, he turned to Gwen and Hermione and said, 'How long have you known?'
'Ages,' Hermione whispered. 'Since we did Professor Snape's essay...'
'I had an inkling,' Lupin said, his eyes catching Gwen's. 'He'll be delighted. He set that essay hoping someone would realise what my symptoms meant. Did you check the lunar chart and realise that I was always ill at the full moon? Or did you realise that the Boggart changed into the moon when it saw me?'
'Both,' said Gwen, quietly, her eyes boring into Lupin's. 'I only guessed. Hermione was the one who really figured it out.'
Lupin forced a laugh.
'You're the cleverest witch of your age I've ever met, Hermione.'
'I'm not,' Hermione whispered. 'If I'd been a bit cleverer, I'd have told everyone what you are!'
'But they already know,' said Lupin. 'At least the staff do.'
'Dumbledore hired you when he knew you were a werewolf?' Ron gasped. 'Is he mad?'
'Some of the staff thought so,' said Lupin. 'He had to work very hard to convince certain teachers that I am trustworthy--'
'AND HE WAS WRONG!' Harry yelled. 'YOU'VE BEEN HELPING HIM ALL THE TIME!' He was pointing at Black, who had crossed to the four poster bed and sunk into it, his face hidden in one shaking hand. Crookshanks leapt up beside him and stepped onto his lap. Gwen and Ron edged away, Ron dragging his leg.
'I've not been helping Sirius,' said Lupin. 'If you'll give me a chance, I'll explain. Look--' He separated Gwen, Harry, Ron and Hermione's wands and threw each back to its owner; Gwen caught hers, stunned.
'There,' said Lupin, sticking his own wand back into his belt. 'You're armed, we're not. Now will you listen?'
The four of them stared at him. Was it a trick?
'If you haven't been helping him,' Harry said, with a furious glance at Black, 'how did you know he was here?'
'The map,' said Lupin. 'The Marauder's map. I was in my office examining it--'
'You know how to work it?' Harry said suspiciously.
'Of course I know how to work it,' said Lupin, waving his hand impatiently. 'I helped write it. I'm Moony-- that was my friends' nickname for me at school.'
'You wrote--?'
'The important thing is, I was watching it carefully this evening, because I had an idea that you, Gwen, Ron and Hermione might try and sneak out of the castle to visit Hagrid before his Hippogriff was executed. And I was right, wasn't I?'
He was pacing up and down, looking at them. 'You might have been wearing your father's old Cloak, Harry--'
'How do you know about the Cloak?'
'The number of times I saw James disappearing under it...' said Lupin, waving an impatient hand again. 'The point is, even if you're wearing an Invisibility Cloak, you show up on the Marauder's Map. I watched you cross the grounds and enter Hagrid's hut. Ten minutes later, you left and set off back to the castle. But you were now accompanied by somebody else.'
'What?' said Harry. 'No we weren't!'
'I couldn't believe my eyes,' said Lupin, still pacing and ignoring Harry. 'I thought the map must be malfunctioning. How could he be with you?'
'No one was with us!'
'And then I saw another dot, moving fast towards you, labelled Sirius Black... I saw him collide with you, I watched as he pulled two of you into the Whomping Willow--'
'One of us!' said Ron angrily.
'No, Ron,' said Lupin. 'Two of you.'
He had stopped his pacing, his eyes moving over Ron.
'Do you think I could have a look at the rat?' he said evenly.
'What?' said Ron. 'What's Scabbers got to do with it?'
'Everything,' said Lupin. 'Could I see him, please?'
Ron hesitated, then pulled a desperately thrashing Scabbers from his pocket; Ron had to seize his long bald tail to stop him escaping. Crookshanks stood up on Black's lap and made a soft hissing noise. Lupin moved closer to Ron. He seemed to be holding his breath as he gazed intently at the rat.
'What?' said Ron again, holding Scabbers close to him, looking scared. 'What's my rat got to do with it?'
'That's not a rat,' said Sirius Black suddenly.
'What d'you mean-- of course he's a rat--'
'No, he's not,' said Lupin quietly. 'He's a wizard.'
'An Animagus,' said Black, 'by the name of Peter Pettigrew.'