Peter Pettigrew transforms back into human form

In the dusty, boarded-up upper room of the Shrieking Shack, the truth that had been hidden for twelve years finally emerged. Ron Weasley, clutching the struggling rat Scabbers to his chest, faced the impossible claim from Sirius Black and Remus Lupin that his pet was actually the wizard Peter Pettigrew. The moment of transformation came when Lupin and Black, standing shoulder to shoulder, raised their wands together. On the count of three, a flash of blue-white light erupted from both wands, freezing Scabbers in midair, his small gray form twisting madly. The rat fell and hit the floor, and another blinding flash of light revealed a man where the animal had been, cringing and wringing his hands.

Identity and Appearance

The man who stood before them was a very short figure, hardly taller than Harry and Hermione. His thin, colorless hair was unkempt, and a large bald patch sat on top of his head. He had the shrunken appearance of a plump man who had lost a great deal of weight in a short time. His skin looked grubby, almost like Scabbers's fur, and something of the rat lingered around his pointed nose and his very small, watery eyes. Even his voice was squeaky. This was Peter Pettigrew, the wizard whom the wizarding world believed had been murdered by Sirius Black twelve years earlier.

The Revelation of the Betrayal

Pettigrew's transformation confirmed the story Black and Lupin had been telling. He had been the Potters' Secret-Keeper, not Black, and it was he who had betrayed Lily and James Potter to Lord Voldemort. When Black had cornered him after the Potters' murder, Pettigrew had faked his own death by blowing apart the street with a curse, killing a dozen Muggles, cutting off his own finger to leave as evidence, and then transforming into a rat to escape into the sewers. He had spent the next twelve years living as a pet, first with the Weasley family, then with Ron at Hogwarts, keeping an ear out for news and waiting to see whether his old master would regain strength.

Confrontation and Confession

Confronted by his former friends, Pettigrew's terror was palpable. He groveled on his knees, shuffling forward with his hands clasped as though praying, first pleading with Black, then turning to Lupin, and finally crawling toward Ron and Hermione, calling himself a good pet and a good friend. When he reached Harry, he whispered that James would have shown him mercy. Black and Lupin, who had rolled up their sleeves and declared their intention to kill him together, were stopped only by Harry's intervention. Harry, though filled with fury, refused to let them become killers, insisting instead that Pettigrew be handed over to the Dementors to be sent to Azkaban.

Escape and Consequences

Before Pettigrew could be taken to the castle, the full moon triggered Lupin's transformation into a werewolf. In the chaos that followed, Pettigrew seized the dropped wand, stunned Ron, and transformed back into a rat, escaping into the darkness. His flight meant that the only living proof of Sirius Black's innocence was gone, and Black remained a fugitive. Yet Dumbledore later told Harry that Pettigrew now owed his life to him, creating a bond that might one day prove significant. The revelation that Scabbers was Peter Pettigrew shattered the story the Ministry of Magic had maintained for twelve years and exposed the true traitor who had caused the deaths of Harry's parents.