At Bellatrix's vault, Harry discovers the Horcrux, Helga Hufflepuff's Cup, despite curses placed on the vault contents, but Griphook takes the sword and abandons the students, as he did not agree to help them leave. The three release the dragon guardian of the vault and fly away. Harry looks into Voldemort's mind and learns that Voldemort has discovered the theft and killed many goblins in retaliation, including Griphook; the sword of Gryffindor disappeared. Voldemort keeps Nagini—his snake and living Horcrux—with him at all times for protection. Harry also learns there is a Horcrux at Hogwarts, in some way related to Rowena Ravenclaw.
Harry, Ron, and Hermione apparate into Hogsmeade, which sets off a Caterwauling Charm alarm. They are rescued by Aberforth Dumbledore, Professor Dumbledore's brother. The discouraged Aberforth instructs a portrait of his younger sister, Ariana to fetch Neville Longbottom, who leads the three friends through a secret passage back to Hogwarts and reunites them with other student allies. Harry asks the students for help in looking for the unknown Horcrux; the only suggestion is the long-lost Diadem of Rowena Ravenclaw, but this has not been seen for centuries.
