“ . . . 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 honors . . .

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

Harry remembered what Mr. Weasley had told Mrs. Weasley. “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 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, who did not look away.

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

And at long last, Harry believed him. Throat too tight to speak, he nodded.

“No!”

Pettigrew had fallen to his knees as though Harry’s nod had been his own death sentence. He shuffled forward on his knees, groveling, his hands clasped in front of him as though praying.

“Sirius—it’s me . . . it’s Peter . . . your friend . . . you wouldn’t . . . ”

Black kicked out and Pettigrew recoiled.

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

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

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

“Forgive me, Remus,” said Black.

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

“Of course,” said Black, and the ghost of a grin flitted across his gaunt face. He, too, began rolling up his sleeves. “Shall we kill him together?”

“Yes, I think so,” said Lupin grimly.

“You wouldn’t . . . you won’t . . . ,” gasped Pettigrew. And he scrambled around to 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?”