Chapter 9: The Half-Blood Prince

At breakfast, Harry tells Hermione and Ron that Draco bragged on the train about a mission. In the Great Hall, Professor McGonagall confirms N.E.W.T. choices; she steers Neville from Transfiguration to Charms and encourages him. Harry and Ron secure Potions with Slughorn despite lacking books and equipment.

In Defense Against the Dark Arts, Snape introduces nonverbal spells and speaks reverently about the Dark Arts. During paired practice, Snape suddenly attacks Harry; Harry responds aloud with Protego, then cheekily says, “There’s no need to call me ‘sir,’ Professor,” earning Saturday detention.

At break, a note from Dumbledore summons Harry to a private lesson on Saturday night, overriding Snape’s detention. Afterward, Harry and Ron struggle through Snape’s homework before double Potions with Slughorn.

Slughorn showcases Veritaserum, Polyjuice, Amortentia, and Felix Felicis, offering the “liquid luck” as a prize for the best Draught of Living Death. Using handwritten tips in a battered Advanced Potion-Making, Harry departs from the textbook method and brews the best potion, winning Felix Felicis. Slughorn praises Harry’s inherited talent and awards points to Hermione for her knowledge.

At dinner, Harry admits he followed the annotated notes. Hermione disapproves, and Ginny warns him about trusting written instructions after her ordeal with Riddle’s diary. When the book falls, Harry notices the inscription: “This book is the property of the Half-Blood Prince,” revealing the source of the marginalia and setting a new mystery.