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 . . . ” An odd shiver passed over his face. “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 toward him, looking concerned, but Ron gasped,

“Get away from me, werewolf!”

Lupin stopped dead. Then, with an obvious effort, he turned to Hermione and said, “How long have you known?”

“Ages,” Hermione 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 realize that I was always ill at the full moon? Or did you realize that the boggart changed into the moon when it saw me?”

“Both,” Hermione said quietly.

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’m trustworthy—”

“AND HE WAS WRONG!” Harry yelled. “YOU’VE BEEN HELPING HIM ALL THE TIME!” He was pointing at Black, who suddenly crossed to the four-poster bed and sank onto it, his face hidden in one shaking hand. Crookshanks leapt up beside him and stepped onto his lap, purring. Ron edged away from both of them, dragging his leg.

“I have not been helping Sirius,” said Lupin. “If you’ll give me a chance, I’ll explain. Look—”

He separated Harry’s, Ron’s and Hermione’s wands and threw each back to its owner; Harry caught his, stunned.

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

Harry didn’t know what to think. Was it a trick?

“If you haven’t been helping him,” he 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—?”