Harry Potter and the Prisoner of Azkaban, Chapters 17-19
These three chapters are the ones in which Harry learns all the truths. Chapter 17 is the equivalent of a shouting match where everyone is pointing the finger at someone else but then they all calm down enough for the next two chapters to get the real story out. I counted about 10 major truth bombs that are laid down in these three chapters.
Truth Bomb (TB) #1 The dog that Harry has been seeing the entire book is actually Sirius Black! He is an unregistered animagus. Being able to turn into a dog is part of what kept Sirius from going mad in Azkaban. Fudge stated earlier in the book that the dementors don’t affect Sirius like they do everyone else because he was too evil, had no remorse, etc. But really he was able to hide from the dementors by becoming a dog. Dementors can’t see they can only feel and they don’t affect dogs like they do humans. The knowledge that he was innocent also kept him grounded.
TB #2 Lupin along with James, Sirius, and Peter Pettigrew made the Marauder’s Map. They were a particularly bright bunch of students (except Peter) and made this very unique, and probably difficult to make, map. They had a penchant for getting into mischief much like Fred and George though they were a bit more reckless.
TB #3 Scabbers is really Peter Pettigrew, another unregistered animagus. He faked his own death, killed all those muggles, and pinned it on Sirius. He turned into a rat to escape and has been in hiding ever since. But he has remained as a pet for a wizard family so that he could stay alert for signs that Voldemort had returned. Peter was never a strong person or wizard and thus attached himself to stronger ones. That is why he was friends with Lupin, Sirius, and James and then later he gave into Voldemort for the same reasons.
TB #4 Lupin, a werewolf, was the source of the shrieks coming from the shrieking shack. The shack, along with the whomping willow, were put in the year that Lupin came to Hogwarts in order to hide his condition. James was also an animagus and they all learned to become one so that they could keep Lupin company while he transformed.
TB #5 Scabbers has been looking ill ever since Sirius escaped because he was afraid that Sirius would tell everyone the truth. It wasn’t because he was scared of Crookshanks, Scabbers had been looking ill even before Hermione got Crookshanks.
TB #6 Crookshanks recognized that Scabbers was an animagus, and evil, from the moment he saw him and the pet store which is why he tried to pounce on Scabbers. Crookshanks is the one that has been helping Sirius get into the castle.
TB #7 Scabbers faked his own death… again to escape Ron and Crookshanks and go into hiding. After Sirius was able to break into the castle he was terrified of Sirius finding him.
TB #8 Sirius convinced Lily and James to change Peter to their secret keeper. He was afraid that he was the obvious choice and Voldemort would come for him for sure. No one would have suspected they would choose Peter because he was so pathetic. It was known that there was a spy within the Potter’s friends. Sirius suspected it was Lupin, Lupin suspected Sirius. But now that everyone knows the truth Lupin and Sirius are bros again.
TB #9 It was Peter that betrayed them not Sirius. Peter had been working for Voldemort for a while and led him straight to the Potters.
TB #10 Sirius escaped Azkaban to find and kill Peter and save Harry. As we will learn more in the remaining books, Sirius and James were best friends. Though they were a foursome, the two of them were particularly close. Very much like Harry and Ron. They would have died for each other and now that James is gone, Sirius feels it is up to him to protect Harry.
So much information is laid out in these chapters and Rowling did a great job of planting clues and red herrings throughout the book to make all of these revelations pay off. Reading it as an adult some of these are fairly obvious but as a kid reading it for the first time my mind was definitely blown. At the end of Chapter 19 it really looks as though everything will work out. Harry and company are all headed to the castle to turn over Peter and clear Sirius, but with three chapters left to go there is still time for things to go wrong, and of course they do. But Harry and Sirius get to have some hope for a few hours.