“Sirius, NO!” Lupin yelled, launching himself forwards and dragging Black away from Ron again, “WAIT! You can’t do it just like that—they need to understand—we’ve got to explain—”

“We can explain afterwards!” snarled Black, trying to throw Lupin off. One hand was still clawing the air as it tried to reach Scabbers, who was squealing like a piglet, scratching Ron’s face and neck as he tried to escape.

“They’ve—got—a—right​—to—know—everything!” Lupin panted, still trying to restrain Black. “Ron’s kept him as a pet! There are parts of it even I don’t understand! And Harry—you owe Harry the truth, Sirius!”

Black stopped struggling, though his hollowed eyes were still fixed on Scabbers, who was clamped tightly under Ron’s bitten, scratched, and bleeding hands.

“All right, then,” Black said, without taking his eyes off the rat. “Tell them whatever you like. But make it quick, Remus. I want to commit the murder I was imprisoned for . . . ”

“You’re nutters, both of you,” said Ron shakily, looking round at Harry and Hermione for support. “I’ve had enough of this. I’m off.”

He tried to heave himself up on his good leg, but Lupin raised his wand again, pointing it at Scabbers.

“You’re going to hear me out, Ron,” he said quietly. “Just keep a tight hold on Peter while you listen.”

“HE’S NOT PETER, HE’S SCABBERS!” Ron yelled, trying to force the rat back into his front pocket, but Scabbers was fighting too hard; Ron swayed and overbalanced, and Harry caught him and pushed him back down to the bed. Then, ignoring Black, Harry turned to Lupin.

“There were witnesses who saw Pettigrew die,” he said. “A whole street full of them . . . ”

“They didn’t see what they thought they saw!” said Black savagely, still watching Scabbers struggling in Ron’s hands.

“Everyone thought Sirius killed Peter,” said Lupin, nodding. “I believed it myself—until I saw the map tonight. Because the Marauder’s map never lies . . . Peter’s alive. Ron’s holding him, Harry.”

Harry looked down at Ron, and as their eyes met, they agreed, silently: Black and Lupin were both out of their minds. Their story made no sense whatsoever. How could Scabbers be Peter Pettigrew? Azkaban must have unhinged Black after all—but why was Lupin playing along with him?

Then Hermione spoke, in a trembling, would-be calm sort of voice, as though trying to will Professor Lupin to talk sensibly.

“But Professor Lupin . . . Scabbers can’t be Pettigrew . . . it just can’t be true, you know it can’t . . . ”

“Why can’t it be true?” Lupin said calmly, as though they were in class, and Hermione had simply spotted a problem in an experiment with grindylows.