Harry Discovers Malfoy's Use of Polyjuice Potion

PAGES: 452-455

Harry realizes that Malfoy is using Polyjuice Potion to disguise Crabbe and Goyle as different students, allowing them to guard the Room of Requirement unnoticed. He suspects Malfoy stole the potion during their Potions lesson. Hermione expresses skepticism about Harry's ability to get into the room without knowing what it transforms into for Malfoy.