Harry, Ron, and Hermione find Mrs. Norris petrified near a mysterious message written on the wall.

Filch blames Harry for attacking Mrs. Norris because he thinks Harry knows he’s a Squib.

Hermione suggests using Polyjuice Potion to learn more about the Heir of Slytherin.

Dobby appears in the Gryffindor common room to warn Harry again.

During a Quidditch match, a rogue Bludger targets Harry, breaking his arm.

Madam Pomfrey uses Skele-Gro to regrow the bones in Harry’s arm after Gilderoy Lockhart removes them.

Dobby visits Harry in the hospital wing and reveals that the Chamber of Secrets has been opened before.

Harry hears voices coming from the Forbidden Forest while recovering in the hospital.

Snape and Lockhart organize a Duelling Club to teach students self-defense.

Harry speaks Parseltongue during the Duelling Club, shocking the other students.

Hermione is petrified after accidentally looking at the Basilisk in a mirror.

Students begin to suspect Harry is the Heir of Slytherin after the Duelling Club.