Harry, Ron, and Hermione spend endless conversations discussing Harry's jaunt into the diary and the possibility that Hagrid could be the culprit. The three students debate asking him, but decide against it, at least until another attack occurred. Meanwhile, the school term continues: the Mandrakes are still maturing, once delighting Professor Sprout by throwing a wild party in their greenhouse, and the Hogwarts second-year students are busy choosing their classes for the following year. Ron and Harry sign up for the same few classes, while Hermione signs up for everything offered. Things are surprisingly normal during this time, and soon the Hufflepuff-Gryffindor Quidditch match draws apace. The evening before the big game, Harry is startled to find that his dormitory room has been broken into, his things torn, broken and rearranged, and Riddle's diary taken. He and Hermione are alarmed to conclude that a Gryffindor must have done it, as nobody else knows the House password.
The morning of the match, Harry hears the hissing, disembodied voice again, and Hermione leaps up and dashes to the library. Harry heads out to the Quidditch pitch, and no sooner than he has taken his position does Professor McGonagall step into the field and stop the game, instructing all students to return to their houses, and Harry and Ron to follow her to the hospital wing, where they find Hermione and a Ravenclaw prefect named Penelope Clearwater, petrified, with a small hand mirror lying next to them. The students all are told to remain in their House common rooms from six P.M. on, and always to be escorted by teachers to and from class. Professor McGonagall adds that the school will likely be closed down unless the attacks are halted. Ron and Harry decide that this is a moment to visit Hagrid. Because of the strict rules about wandering around unchaperoned, they decide to do this underneath Harry's invisibility cloak, a gift left to him by his late father.
The boys set out late that night, and as soon as they enter Hagrid's small wooden cabin, they hear a knock at the door and hide invisibly in a corner. Dumbledore enters with a man Ron immediately recognizes as Cornelius Fudge, the Minister of Magic. Fudge explains apologetically to Hagrid that in light of the present circumstances, he must ask him to leave Hogwarts and reside in Azkaban, a frightful wizard prison, until the events stop or are solved. Dumbledore states calmly that he trusts Hagrid entirely, but Fudge says that he must act or else the ministry will think he is doing nothing to stop the attacks, and since Hagrid's history is muddled with rumors about the Chamber of Secrets, he should be the Ministry's first target. While this is being discussed, the door opens again, and Lucius Malfoy enters, explaining icily that the twelve school governors have signed a petition calling for Dumbledore to step down as headmaster. Dumbledore consents without argument, saying only these portentous words, "You will find that I will only truly have left this school when none here are loyal to me. You will also find that help will always be given at Hogwarts to those who ask for it." Hagrid leaves more reluctantly, calling out behind him two instructions heard by Harry and Ron: to follow the spiders to find the culprit, and to feed Fang, his dog.
With the break-in to his dormitory, Harry has further cause for alarm: the criminal of that endeavor must be someone he knows, someone who is in Gryffindor, someone he had up until that point trusted. The Heir of Slytherin speculation shifted away from Malfoy after the Polyjuice affair, but now it is away from Slytherin altogether, leaving Percy, due to his earlier suspect positions, as a more likely threat, but really anyone in the House could now be responsible. After Hermione is petrified while all of Hogwarts is outside watching the Quidditch match, the circumstances become more threatening; the creature responsible for the crime may not even be a student. With the diary gone, Harry can no longer communicate with Riddle, and so the burden of discovery lies entirely on him alone.
Harry and Ron's decision to slip out of their dorms and question Hagrid is one of obligation to their involvement in the crisis. Harry wound up with the diary, he spoke with Tom, and now he feels it his responsibility to cut to the core of the mystery in any way he can, even at great personal risk. Ron, as loyal as ever, accompanies him. This is the quintessential origin of Harry's heroism at Hogwarts; he is bold enough to break rules in search of evidence, and his situation brings together personal interest (keeping Hogwarts open and functioning so that he can remain there instead of with the Dursleys) and a general sense of integrity (a need to do everything he can to help stop the attacks on his community).
The boys are handicapped by not having Hermione with them. Hermione pieces facts together in a way that could only be possible for someone as well-read as she. Having her petrified leaves Ron and Harry to figure out the information that Hermione sought. With her out of the picture, the two boys must be more alert than ever, since their way of discovery is trial-and-error exploration, while Hermione's is based more on research. Here Ron and Harry must do both, and the need to revive the victims is more pressing than ever, now that their best friend is one of them. The mirror next to them serves as evidence, but of what we do not yet know. Obviously Hermione had learned that the monster in the Chamber was somehow rendered less dangerous by a mirror, but what she found is useless until the Mandrake potion will be ready.
The rogue bludger doesn't cause Harry to lose the bones in his arm, Lockhart does