Filch spies Mrs. Norris hanging from the ceiling, and explodes at Harry, accusing him of killing the cat. Dumbledore appears at this time and whisks Harry, Ron, Hermione, Filch and Mrs. Norris away, into Lockhart's nearby office, which Lockhart eagerly volunteered. They sit tensely among all of Lockhart's preening portraits of himself. Dumbledore examines the cat, Professor McGonagall frets quietly, and Snape sneers. Lockhart reassures them all in his curse-reversing expertise and Filch sobs. Dumbledore explains that the cat is not dead, but petrified, and that second- year students could not have possibly mastered the magic necessary for that degree of a dark spell. Dumbledore also says that soon the school will have enough grown Mandrakes to make a restorative potion, which Lockhart eagerly volunteers to make. Filch is unconvinced and explains that Harry knows he is a Squib and therefore attacked his cat, and Snape interrupts and says that the three students were in a peculiar place on the night of the Halloween feast. Ron, Harry, and Hermione explain the Deathday party, and Snape asks why they didn't come straight to the feast afterwards. Not wanting to explain about the eerie, disembodied voice, Harry explains that they were tired and wanted to go to bed. Snape does not believe them and recommends that Harry be taken off the Quidditch team until he is ready to tell the truth. McGonagall and Dumbledore quickly say that this will not be necessary. The three students walk up to their dorms, Ron explains what a Squib is, and Harry ponders what the Chamber of Secrets could possibly be.
Filch keeps a close watch on the scene of the crime, Justin Finch-Fletchley runs from Harry, seeming to believe that he is the instigator of the crime, and Ginny Weasley seems in utter terror of everything. In History of Magic class, while Professor Binns, the small, elderly, and boring ghost who teaches it, drones on, Hermione raises her hand and persuades him to explain the history of the Chamber of Secrets. We then learn that the original founders and namesakes of the four houses created Hogwarts as a place to bring up bright young witches and wizards, and that all went smoothly until Salazar Slytherin offended the other three by expressing his wish to exclude all Muggle-born wizards from the school. Slytherin left the school over this disagreement, but only after he built a hidden Chamber of Secrets, which contained a monster that would wipe out all non-pureblood wizards from Hogwarts. He said that only his heir would be able to control it. The students bombard Binns with questions until he grows annoyed, says it's all folklore, and returns to the original lesson plan.
This knowledge causes Harry to worry. When he was sorted by the hat the previous year, the Sorting hat had told him that Slytherin would make him great. When Harry thought how much he didn't want to be in Slytherin, the hat placed him in Gryffindor. He hopes he is not somehow connected to Salazar Slytherin. However, much of the school seems to think that he is. As Harry, Ron, and Hermione walk through the corridor with the writing on the wall, speculating where all the water came from the night of the attack and noticing a line of spiders hastily escaping through the window, they decide to look into Myrtle's bathroom for clues. Myrtle is as gloomy as ever, and the bathroom itself is rather depressing as well. After a few minutes they leave, only to run into Percy Weasley, who scolds them terribly for being in a girls' bathroom and for being in a suspicious place; this exchange upsets both Ron and himself.
That night, Harry, Ron, and Hermione speculate on whether Malfoy is the Heir of Slytherin, and Hermione suggests that they could find out by making a Polyjuice potion, thus turning themselves into Slytherins and eavesdropping on Malfoy in their House common room. Ron and Harry are skeptical, but Hermione persists, saying that she could have a teacher write her a note to check out a book from the restricted section of the library, where that potion would be.
In this chapter, Harry is burdened with secrets; first, he worries about the voice he has been hearing. He knows that a teacher would not believe him and he even questions whether Ron and Hermione believe him. He can think of no explanation for this phenomenon. Furthermore, he is worried that he is a Slytherin. From the beginning of the first book in the series, Harry was alarmed at the thought of getting placed into Slytherin House. He met Malfoy in Diagon Alley and from him learned about Slytherin's history, and from that moment on, he was wary both of Malfoy and of the House. The idea that a voice speaks of killing students terrifies Harry, and he is terrified further at the idea that he might be involved in a way he doesn't understand.
It doesn't help that other students are beginning to suspect him. He is an easy target, however, and he becomes more of one throughout certain events in coming chapters. In this situation, Snape severely mistrusts him. Dumbledore does trust him, and McGonagall is strict, but is a sports fan and so is adamant that Harry remain on the Gryffindor Quidditch team. Harry is witnessing strange and frightening things, but he does not want to acknowledge that he could be anymore involved than anyone else. Trouble at Hogwarts often affects Harry, since the trouble always has Voldemort behind it in some way. Harry refuses to alert the teachers about the voice he is hearing.
J.K. Rowling makes the culprit very unclear and ambiguous. By the end of this chapter, when Hermione is conjuring up ways to slip into the Slytherin common room and prove that Malfoy as Slytherin's heir, the reader would have a good reason to suspect Malfoy; we know that he has called Hermione a Mudblood and grinned at the immobile petrified cat. He has ancient family roots in the Slytherin House, and he seems just malicious enough to be responsible for the harm caused. Furthermore, Percy Weasley is in a suspicious place at a suspicious time, and is extraordinarily upset at Ron for being there, too. Both of these boys could be seen as possible culprits. Rowling frames many different characters as possible culprits, including Harry himself, before she reveals the truth.