CHAPTER EIGHTEEN

Sirius Black lunges for Scabbers, intent on killing Peter Pettigrew, but Remus Lupin restrains him, insisting Harry, Ron, and Hermione hear the full truth first. Ron and Harry reject the claim that Scabbers is Pettigrew, citing witnesses to Pettigrew’s death, while Sirius and Lupin insist the witnesses were mistaken. Hermione challenges the idea with Ministry records, prompting Lupin to reveal there were three unregistered Animagi at Hogwarts.

Lupin explains his childhood werewolf bite and how Dumbledore enabled his schooling by creating the tunnel and Shrieking Shack for his monthly transformations, with the Whomping Willow guarding the entrance. Before the Wolfsbane Potion, his transformations were violent; the Shack’s screams created its haunted reputation. Fearing rejection, Lupin hid the truth from his friends until they worked it out.

Instead of abandoning him, James Potter, Sirius Black, and Peter Pettigrew illegally became Animagi over three years so they could accompany Lupin safely. With Peter small enough to freeze the Willow, they joined Lupin during full moons, reducing his danger. Their nocturnal explorations led them to create the Marauder’s Map and adopt the nicknames Padfoot, Wormtail, and Prongs.

Hermione criticizes the recklessness; Lupin admits there were near misses and confesses lasting guilt over betraying Dumbledore’s trust. He further reveals he refrained from telling Dumbledore that Sirius is an Animagus, partly out of shame for past rule-breaking, inadvertently validating Snape’s suspicions about him.

Lupin recounts a school incident where Sirius told Severus Snape how to reach the Shack; James rescued Snape at great risk before he met a werewolf, but Snape learned Lupin’s secret and has hated them since. As Lupin finishes, a cold voice interrupts: Snape removes an Invisibility Cloak and levels his wand at Lupin, abruptly shifting the power in the room.