Harry Potter and the Sorcerer's Stone Chapter 9 - The Midnight Duel
Harry realizes that he hates Draco Malfoy even more than Dudley Dursley - a sentiment he previously thought impossible. When notices for flying lessons appear, everyone realizes that Slytherin and Gryffindor will be competing. Harry worries about flying in Quidditch tournaments because he has no idea how to do so, while Ron reassures him that Draco is just bragging about his flying abilities. Neville is such a klutz, that he has never been allowed to fly before, while Hermione recites rule after rule about flying and Quidditch from various texts she has read in the library. Neville receives a package from home called a Remembrall, a ball that tells you if you've forgotten something. Draco walks by and snags Neville's Remembrall, hoping to start a fight between the two houses. Professor McGonagall stops them and Draco returns the Remembrall.
Madame Hooch, the flying teacher, gathers the students together and teaches them the intricate method of mounting their brooms and lifting up into the air. When Neville attempts to fly, his broom zooms into the forest, leaving him fallen flat on the ground with a broken wrist. Madame Hooch tells everyone to stay put still while she takes him to the hospital. However, as soon as they are gone, Draco Malfoy steals the Remembrall and flies into the air alone, teasing Harry and his friends. An enraged Harry mounts his broom and flies after Malfoy, realizing the simplicity, joy, and wonder of flying through the air on a broom. He informs Malfoy that he is alone without his gang and catches the Remembrall as Malfoy flies down to the ground. Suddenly Professor McGonagall screams Harry's name in outrage, as he has flown in the air without permission and may now be expelled from Hogwarts. She leads him through the school to seek a boy named Oliver Wood, the head of the Gryffindor Quidditch team. After seeing Harry dive fifty feet and catch the Remembrall his first time on a broom, she realizes his power and skill, and gives him the position of Seeker on the Quidditch team. He is the only first year to ever have this honor and place. Ron is shocked to hear of such amazing news for his friend.
The older boys on the Quidditch team come up to Ron and Harry, who are eating in the banquet hall, excited to meet their new teammate. Malfoy and his gang also speak to Harry, wondering when he will be expelled. They are surprised to learn that he has been rewarded instead of punished for flying on his broom, and invite him to a midnight wizard's duel. Ron claims that Harry will accept and that he will be his second. Harry doesn't understand anything that is going on, but accepts to fight, nonetheless. After they have left, Hermione walks up to Harry and Ron, upset that they will fight. She thinks it selfish and unfair for Harry to go around at night losing points for Gryffindor.
When Ron and Harry exit Gryffindor Tower at approximately 11pm, Hermione is waiting for them near the exit to stop them from risking a loss of valuable points. She follows them out, and is locked out of the tower, for the hole through which they climbed - with the fat lady - is no longer there, and she must wait for her to return to the painting in order to go through the painting and into the Tower.
Hermione follows them to the duel. They walk through the classrooms and hope to find Malfoy. They find Neville waiting outside the Tower, healed from his arm injury, but confused as to the password to get back inside. Instead of finding Malfoy the four stumble across Filch speaking to his cat, Mrs. Norris. They fear getting caught and run through the trophy room. Ron realizes that they must return to Gryffindor as soon as possible. Hermione informs them that Malfoy had tricked them into venturing into the Trophy room against the rules. Filch chases them until they find themselves lost in a corridor - the forbidden corridor on the third floor. It is guarded by a large animal with three heads over a trapdoor.
"They were looking straight into the eyes of a monstrous dog, a dog which filled the whole space between ceiling and floor. It had three heads. Three pairs of rolling, mad eyes; three noses, twitching and quivering in their direction; thee drooling mouths, saliva hanging in slippery ropes from yellowish fangs." Chapter 9, pg. 119
The kids run as fast as they can to escape death, this monstrous animal guarding, what Hermione reveals, is a trapdoor. The fat lady in the portrait has returned and Harry tells her the secret password of "pig snout." Her door opens and the kids climb through and fall asleep. Harry realizes that the only place more secure and safe than Gringotts is Hogwarts. Now, he realizes where the little package from the vault is located: under the trapdoor.