"If you want to kill Harry, you'll have to kill us too!" Ron shouted, standing up on his broken leg to face Sirius.

"And me too!" Christina squeaked, hiding behind Ron.

Sirius's face changed when he saw her, going from surprise to recognition to surprise again. "You're her." He whispered. "I'd know those eyes anywhere. You're really her."

"He's going to kill me." Christina squeaked.

"No. Only one will die tonight."

"Why's that?" Harry yelled. "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." Hermione muttered.

"HE KILLED MY MUM AND DAD!" Harry roared.

"Just Dad." Christina whispered. She wanted to correct him, but she couldn't find the voice to do it.

But Harry had leapt forward and was pummeling Sirius, grabbing his wrists and forcing him against the wall.

"Harry no!" Hermione shouted, but he didn't listen. He knocked Sirius down and stood over him, lowering his wand into Sirius's face.

"You killed my parents."

"I don't deny it." Sirius whispered. "But if you knew the whole story."

"What story? You sold them to Voldemort. That's all I need to know." He lifted his wand again, but hesitated as he leveled it at Sirius's face. He paused like that for a long moment, Hermione glaring at him and Christina trying to blend into the bed's grey blankets.

But the moment had passed. Footsteps and muffled voices could be heard in the room below.

"We're up here!" Hermione shouted. "Sirius Black! Quick!"

Lupin burst into the room, Lily at his heels. "Expeliarmus!" He shouted, at the same time that Lily shouted, "Harry get off him!"

Harry reeled backward as his wand soared from his hand, his face white with shock, and Lily stepped forward to pull Sirius off the ground.

"Mum?"

"Harry." Lily swiftly hugged him. Oh how he resembled James. Remus had been right. Unsure of what to say, she muttered, "And that's your own godfather you're trying to kill."

"Lily." Sirius looked more like a ghost now than he ever had.

"Sirius." She pulled him into a hug.

"You and the little one. Alive." Sirius muttered. "How?"

Christina had a sneaking suspicion that she was "the little one" and was about to protest being called such, but didn't want to argue with a man who looked like something out of the Haunted Mansion ride at Disney.

"It really wasn't you, huh?" Lupin stepped forward and joined the hug.

"I don't believe it!" Hermione screamed. "You—you and him—"

"Hermione." said Lupin.

"This whole time, you've been helping him! Harry, he wants you dead too, he's a werewolf!"

"Not at all up to your usual standard, Hermione." said Lupin after a brief silence. "Only one out of three, I'm afraid. I haven't been helping Sirius and I don't want Harry dead. But I am a werewolf. How long have you known?"

"Since doing Snape's werewolf essay." Hermione replied haughtily.

"Only Severus would do something that underhanded." Lily muttered.

"But you need to listen to me, Harry, Hermione." Lupin continued. "Sirius is innocent."

"No he's not!" Harry shouted. "He sold my mum and dad out to Voldemort!"

"He didn't." Lily's words were quiet, but she commanded everyone's attention. "Sweetheart, do you know about the fidelius charm?"

"Give me my wand."

"Harry, listen to your mother." said Remus. "There's some things you need to know before you do anything rash. Do you know about the fidelius charm?"

Harry nodded.

"Sirius was indeed our secret keeper for a long time." said Lily. "But he and your father were best friends for so long, we were worried someone would figure it out. So we switched, at the last minute, to someone else."

"I convinced them to change secret keepers." Sirius said. "It is my fault. I told them to use a person who later betrayed them. Harry, hate me all you want. I'm to blame for this happening."

"Harry." Lily took his hand. "I know this is a lot right now. But there's a lot of information you need to know before you try to kill anyone." Harry nodded, clinging to her hand a little tighter. The wheels in his brain seemed to be turning very fast. Finally he said,

"But who was it? Who sold you out to Voldemort?"

"Someone I believed to be dead, up until tonight." Lupin said. "Until I saw him on the marauder's map. The map never lies. I know, because I was one of its creators."

"You what?" Harry gaped.

"One story at a time, Remus." said Lily.

"Right. Where is he, Sirius?"

Sirius pointed to Ron. "The rat."

"What's Scabbers got to do with this?" Ron asked. "He's just a rat!"

"He's not." said Sirius. "He's an animagus. By the name of Peter Pettigrew."

Silence, then, "No he's not." It was Hermione. "We learned all about animagi in McGongall's class. I looked at the list, and there have only been seven animagi registered this century!"

"Wrong again, I'm afraid, though I admire your dedication to your studies." said Lupin. "Little does the ministry know, there used to be three unregistered animagi running around Hogwarts. Allow me to explain. You see, back when I was at Hogwarts, there was no wolfsbane potion. Instead, once a month, Madam Pomfrey lead me through the passage here to the shrieking shack, where I transformed. My transformations were every painful, and no one could accompany me for fear of being bitten. My friends, my best friends, decided to learn to become animagi. As animals, they would be able to safely accompany me during my transformations. Sirius here became a dog, Padfoot. James was Prongs, a stag. Peter was Wormtail. A rat."

Harry frowned. "Mum, did you know about this?" There was a note of incredulity in his voice, and he very clearly wanted her to verify this story.

"I didn't start dating your dad until seventh year, so I was not privy to most of this. I heard the rumors that Remus was a werewolf and chose not to believe them. As for the bit about them being animagi, well, it was easy enough to figure out if you knew what to look for. Remus could sometimes be seen hanging out with a big black dog or a friendly deer. I knew Remus didn't have a dog and I also knew that the deer around here aren't usually this friendly with humans, and besides, the dog only ever ate potions homework. James didn't show me his animagus form until after we graduated for fear I'd tell McGonagall."

"And you should've, if you'd known!" said Hermione. "That was so dangerous! And—and you could've bitten someone, if something had gone wrong!" She was looking scandalized.

"I debated telling Dumbledore, at the start of this school year, that Sirius was an animagus." said Lupin. "In the end, I didn't. I didn't want him to know, even now, that I'd betrayed his trust. Snape thinks I've been helping Sirius this whole time, and he's not really wrong in that sense."

"Snape's just out to get you!" Harry shouted. "He hates you because you were friends with my dad!"

"No, there was more to it than that." said Lupin heavily. "Sirius played a trick on Severus Snape once, a trick that involved me. See, Severus was always very curious about where I went every month."

"He started a lot of the rumors about Remus being a werewolf." Lily added. "The bastard." Harry looked at her quizzically. He seemed to pick up on the fact that she knew Snape well, but there was no time to ask about that.

"Anyway, Sirius told Severus about the tunnel beneath the willow, and Severus went down that way on the full moon. Your father, realizing what was about to happen, went down there and pulled him back, at great risk to his own life. But Severus knew what I was, and was forbidden to tell anyone."

"And that's why he doesn't like you?" Harry asked. "Because he thinks you wanted to hurt him?"

"That's right." a cold voice sneered. Snape opened the door all the way, pulled off the invisibility cloak, and pointed his wand directly at Lupin.