Gilderoy Lockhart's Fraud and Downfall
Harry Potter and the Chamber of SecretsThe celebrated Defense Against the Dark Arts teacher is revealed to be a fraud who takes credit for others' deeds, ultimately losing his memory.
increasing
Bearing strength in each event
decreasing
Lockhart's Arrival and Popularity

The Celebrity Teacher
The Book Signing
Gilderoy Lockhart arrives at Hogwarts as the new Defense Against the Dark Arts teacher, greeted with fanfare. He signs books at Flourish and Blotts, posing for photos and declaring himself a hero. Hermione is starstruck.
The Incompetent Teacher
Lockhart's classes are a disaster. He releases Cornish pixies, which wreak havoc, and fails to control them. He assigns homework about himself and forces students to act out scenes from his books. He is clearly incompetent.
The Illusion of Bravery
Lockhart constantly boasts about his adventures, but his actions reveal cowardice. He avoids danger and takes credit for others' achievements. His true nature is gradually exposed.
The Dueling Club Humiliation

A Public Embarrassment
The Demonstration
Lockhart starts a Dueling Club with Snape as his assistant. He attempts a demonstration but is easily disarmed by Snape. He later tries to teach defensive moves but fails to block a spell.
The Serpent Incident
When Draco Malfoy conjures a snake, Lockhart tries to remove it but instead makes it angry. Harry speaks Parseltongue to calm it, which causes suspicion. Lockhart's incompetence is fully on display.
The Aftermath
Lockhart's reputation suffers, but he continues to brag. The students begin to see through his facade. The incident also reveals Harry's Parseltongue ability, which later fuels rumors about him being the Heir.
The Confession and Memory Loss

The Truth Comes Out
The Failed Memory Charm
When Harry and Ron force Lockhart to accompany them to the Chamber, he tries to use a Memory Charm on them. The spell backfires due to Ron's broken wand, hitting Lockhart instead. He loses his memory completely.
The Unmasking
Before the spell, Lockhart admits that he never performed the feats in his books. He used Memory Charms on the real heroes and took credit. He is a fraud, not a hero.
The End of a Career
Lockhart is taken to the hospital wing, having no idea who he is. He later leaves Hogwarts to recover his memory. The school is relieved to be rid of him, and the Defense Against the Dark Arts post remains vacant.
beginning of term, September
December
after Ginny's abduction, late May