Harry Potter and the Prisoner of Azkaban: Chapter 18 Summary.
Moony, Wormtail, Padfoot and Prongs
Chapter 18 of Harry Potter and the Prisoner of Azkaban, titled “Moony, Wormtail, Padfoot and Prongs” continues the tense situation that the trio have found themselves in, and reveals some shocking secrets.
The Truth about Peter Pettigrew
Ron, Harry, and Hermione are stunned by the claim that Scabbers is actually Peter Pettigrew. Ron voices their disbelief, calling Sirius and Lupin mental. Harry insists that Pettigrew is dead and accuses Sirius of killing him. Sirius admits he had meant to kill Peter but was outwitted at the last second, something that he wouldn’t let happen this time.
Sirius lunges at Scabbers, causing his weight to fall on Ron’s broken leg. Lupin pulls Sirius back, and urges him to explain everything first. Sirius resists, but eventually agrees. Ron, still disbelieving, tries to leave. Lupin, pointing his wand at Scabbers, insisting that Ron listens, and maintains a hold on ‘Peter’ while he does so. Ron yells that Scabbers is just a rat, and struggles to force him into his pocket. Harry supports Ron, helping him stay seated.
Harry argues that witnesses had seen Pettigrew die. Sirius, still fixated on Scabbers, claims that they had been deceived. Lupin confirms he had also believed Pettigrew was dead, until he saw Peter’s name on the Marauder’s Map. The map never lies, meaning that Peter was alive. Harry and Ron exchange glances, now convinced that Lupin had lost his mind.
Hermione tries to reason with Lupin, insisting that Pettigrew could not be an Animagus since the Ministry kept close tabs on all Animagi. Lupin laughs, and reveals that while that is usually the case, the ministry had no idea about the three unregistered Animagi of Hogwarts; James Potter, Sirius Black, and Peter Pettigrew.
The Secret of the Marauders
Sirius grows impatient by the minute, and demands that Lupin hurries. Lupin resumes his explanation, but is interrupted by a creaking noise. The door opens behind them, but nobody enters. Ron suggests the house was haunted, but Lupin dismisses it. He explains that the screams the villagers had heard had come from no one other than himself.
Lupin was a werewolf, who had been infected as a kid. No cures for lycanthropy had existed back then, and he became a full-fledged werewolf every month. Dumbledore had allowed Lupin to attend Hogwarts despite his condition, and had made special arrangements to keep others safe.
The Shrieking Shack and the Whomping Willow had been set up to conceal his transformations. Villagers mistook his painful howls for evil spirits, and Dumbledore encouraged the rumor to keep them away from the shack. However, despite his condition, Lupin had found happiness at Hogwarts.
He had made three great friends: James Potter, Sirius Black, and Peter Pettigrew. Lupin had tried to hide his condition, but they figured it out. Instead of abandoning him, they turned into unregistered Animagi to support him.
James became a stag, Sirius a large dog, and Peter a rat. It took them three years to master the transformation, and they managed to pull it off in their fifth year.
The Marauders’ Adventures
Their Animagus forms allowed them to accompany Lupin safely. Werewolves were only dangerous to humans, so their presence calmed him.
They sneaked out every full moon, using James’s Invisibility Cloak. Peter, as a rat, deactivated the Whomping Willow by touching the knot that froze it. From there, the three accompanied Lupin through the passage to the shack.
With his friends, Lupin became less dangerous. Eventually, they started roaming beyond the Shrieking Shack, exploring Hogwarts and Hogsmeade. Their adventures led them to create the Marauder’s Map. Their nicknames—Padfoot, Wormtail, and Prongs had actually come from their Animagus forms.
Hermione questions the recklessness of running around with a werewolf. Lupin admitted that they were young and careless, and had actually had a few near misses. He had felt guilty for betraying Dumbledore’s trust but always tried justified it to himself. Lupin also confessed to struggling all year over whether to tell Dumbledore that Sirius was an Animagus. He ended up not being able to confess, fearing the revelation of his own past mistakes.
To ease his guilt, Lupin had convinced himself that Sirius was using dark magic to enter Hogwarts. In a way, Snape had been right about him all along.
Snape’s Revenge
At the mention of Snape, Sirius looks up from Scabbers for the first time. Lupin revealed that Snape was now a professor at Hogwarts and had opposed his appointment.
Snape had disliked Lupin because of an old grudge. Sirius had once played a very dangerous prank on Snape, which had nearly lead him to a deadly encounter with a transformed Lupin.
James however, at a great risk to his own life had managed to save Snape, just in time. Dumbledore forbade Snape to speak of this incident, but Snape could never forgive the Marauders.
Harry realizes that Snape despises Lupin because he thought Lupin had been involved in the prank. Before Lupin can respond, however, a cold voice confirms Harry’s suspicion.
The chapter ends on a tense note, as the cold voice is revealed to belong to Severus Snape, who had been hidden beneath an invisibility cloak all along.
