The wooden ground lurched and the area around Black turned into sawdust. Black plummeted downwards into the opening below.

"We have to go!" Edward commanded but Harry was looking furiously at where Black had disappeared.

"Harry!" Edward shouted, trying to snap the boy back into attention. Harry whirled on him, eyes blazing. "You need to go before Black comes-"

"Comes back?" A whimsical voice said from the doorway. Black was leaning against the door frame, above the open hole. Then, Edward realised he was levitating himself.

"There'll be only one murder here tonight," said Brack, and his grin widened.

"Why's that?" Harry spat, trying to wrench himself free of Weasley's and Granger's grips. "Didn't care last time, did you? Didn't mind slaughtering all those Muggles to get at Pettigrew... What's the matter, gone soft in Azkaban?"

"Harry!" Granger whimpered. "Be quiet!"

"HE KILLED MY MUM AND DAD!" Harry roared, and with a huge effort he broke free their restraint and lunged forward.

Granger was screaming; Weasley was yelling; there was a blinding flash as the wands in Black's hand sent a jet of sparks into the air that missed Harry's face by inches. Harry was punching Black wildly and uncontrollably. Punches that were haphazardly aimed and would not even bruise a child.

Edward ignored the protests of the two Gryffindors behind him and charged towards Black.

Black's free hand had found Harry's throat.

"No," the haggard man hissed, "I've waited too long."

Edward swung his foot at Black's head, knocking the wind out of him. Black grunted and let go of Harry. Granger seized the hocus pocus stick from his hand.

Black tried to retaliate by aiming a swipe at Edward who blocked it with his automail arm. Edward twisted the convict's arm behind his back and Black let out a hiss of outrage.

"Argh!"

Edward turned around to see that the fat cat had joined the fray. Both sets of front claws had sunk

themselves deep into Harry's arm. Harry threw him off, but the fat cat was darting toward Harry's hocus pocus stick.

"NO YOU DON'T!" roared Harry, and he aimed a kick at the cat that made the cat leap aside, spitting. He snatched up his wand.

In the confusion, Edward let his guard slip and Black wrapped a skinny arm around his throat.

"Get out of the way!" Harry shouted at Edward who raised an eyebrow and pointed at the chokehold. He was trying his best not to gag. That would look uncool.

Harry pointed the stick in between Black's eyes.

"Going to kill me, Harry?" Black whispered.

"You killed my parents," said Harry, his voice shaking slightly, but his hand was quite steady. Edward was thankful for that. He did not know want to know what would happen if Harry shot him by mistake.

"I don't deny it," Black said very quietly. "But if 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, and there was a note of urgency in his voice now. "You'll regret it if you don't... You don't understand..."

"I understand a lot better than you think," said Harry, and his voice shook more than ever. "You never heard her, did you? My mum... trying to stop Voldemort killing me... and you did that... you did it..."

Before either of them could say another word, something ginger clambered up Edward's face. It was the fat cat. It settled himself on Black's head.

"Get off," he murmured, trying shake the fat cat off him.

Harry stared down at Black and the cat, his grip tightening on the stick.

Edward thought Harry was really going to kill both Black and the cat at the same time.

Harry raised the wand and Edward closed his eyes, hoping that Harry would miss him.

And then came a new sound. Muffled footsteps were echoing up through the floor- someone was

moving downstairs.

"WE'RE UP HERE!" Granger screamed suddenly. "WE'RE UP HERE – SIRIUS BLACK - QUICK!"

Black made a startled movement and Edward's eyes flew open. He grabbed the hand that was choking him and yanked it away with all his strength. The footsteps were thundering up the stairs.

The door of the room burst open in a shower of red sparks and Edward wheeled around as Lupin came hurtling into the room, his face bloodless, his stick raised and ready. His eyes flickered over Edward, gasping for breath, over Weasley, lying on the floor, over Hermione, cowering next to the door, to Harry, standing there with his wand covering Black, and then to Black himself, crumpled and bleeding at Harry's feet.

"Expelliarmus!" Lupin shouted.

Harry's wand flew once more out of his hand so did the two Hermione was holding. Lupin caught them all deftly, then moved into the room, staring at Black, who still had the fat cat lying protectively on his head. It looked kind of funny if everyone was not about to kill one another.

Then Lupin spoke, in a very tense voice.

"Where is he, Sirius?"

Edward looked quickly at Lupin. There was some familiarity in the way Lupin talked to Black. As if they were long lost brothers.

Black's face was quite expressionless. For a few seconds, he did not move at all. Then, very slowly, he raised his empty hand and pointed straight at Weasley. Weasley looked dumbfounded.

"But then..." Lupin muttered, staring at Black so intently it seemed he was trying to read his mind, "why hasn't he shown himself before now? Unless-" Lupin's eyes suddenly widened, "-unless he was the one... unless you switched... without telling me?"

Very slowly, his sunken gaze never leaving Lupin's face, Black nodded.

"Professor," Harry interrupted loudly, "what's going on?"

Lupin lowered his stick, walked to Black's side, seized his hand, pulled him to his feet so that the cat fell to the floor, and embraced Black like a brother.

"I DON'T BELIEVE IT!" Hermione screamed.

Lupin let go of Black and turned to her. She had raised herself off the floor and was pointing at Lupin, wild-eyed. "You - you -"

"Hermione -"

"- you and him!"

"Hermione, calm down -"

"I didn't tell anyone!" Hermione shrieked. "I've been covering up for you -"

"Hermione, listen to me, please'" Lupin shouted. "I can explain -"

Harry could feel himself shaking, not with fear, but with a fresh wave of fury.

"I trusted you," he shouted at Lupin, his voice wavering, out of control, "and all the time you've been his friend!"

"You're wrong," said Lupin. "I haven't been Sirius's friend, but I am now- Let me explain!"

"NO!" Granger screamed. "Harry, don't trust him, he's been helping Black get into the castle, he wants you dead too- he's a werewolf!"

"A what?" Edward asked but no one was listening to him.

"Not at all up to your usual standard, Hermione," Lupin 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. An odd shiver passed over his face. "But I won't deny that I am a werewolf."

"What's that?" Edward asked Weasley who looked frightened and did not acknowledge him.

"How long have you known?" Lupin said quietly.

"Ages," Granger whispered. "Since I did Professor Snape's essay..."

"He'll be delighted," said Lupin coolly. "He assigned that essay hoping someone would realize 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," Granger said quietly.

Lupin forced a laugh. "You're the cleverest witch of your age I've ever met, Hermione."

"I'm not," Granger 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." Weasley gasped. "Is he mad?"

"Some of the staff thought so," said Lupin. "He had to work very hard to convince certain teachers that I'm trustworthy-"

"AND HE WAS WRONG!" Harry yelled. "YOUVE BEEN HELPING HIM ALL THE TIME!"

"I have not been helping Sirius," said Lupin. "If you'll give me a chance, I'll explain. Look-"

He tossed the wands back to the Gryffindors.

"There," said Lupin, sticking his own wand back into his belt "You're armed, we're not. Now will you listen?"

"If you haven't been helping him," Edward said, with a glance at Black, "how did you know he was here?"

"The map," said Lupin. "The Marauder's Map."

"It was in my room!" Edward protested.

"What?" Harry said. "No wonder the map I have didn't work!"

"Quiet, Harry!" Edward hissed. "How did you know the map-"

"Was with you? I didn't. Crabbe did."