Draco Malfoy
This book also focuses on the mysterious activities of Harry's rival Draco Malfoy. Voldemort has coerced a frightened Malfoy into attempting to kill Dumbledore. During a duel in Moaning Myrtle's bathroom, Harry uses the Half-Blood Prince's spell, "Sectumsempra," on Malfoy, who suffers near-fatal injuries as a result. Harry is horrified by what he has done and also comes to feel sympathy for Draco, after learning he was forced to do Voldemort's bidding under the threat of his and his parents' deaths.