魔法部
Hermione and Ron form "Dumbledore's Army", a secret study group in which Harry agrees to teach his classmates the higher-level skills of Defence Against the Dark Arts that he has learned from his previous encounters with Dark wizards. Through those lessons, Harry begins to develop a crush on the popular and attractive Cho Chang. Juggling schoolwork, Umbridge's incessant and persistent efforts to land him in trouble and the defensive lessons, Harry begins to lose sleep as he constantly receives disturbing dreams about a dark corridor in the Ministry of Magic, followed by a burning desire to learn more. An important prophecy concerning Harry and Lord Voldemort is then revealed, and Harry discovers that he and Voldemort have a painful connection, allowing Harry to view some of Voldemort's actions telepathically. In the novel's climax, Harry is tricked into seeing Sirius tortured and races to the Ministry of Magic. He and his friends face off against Voldemort's followers (nicknamed Death Eaters) at the Ministry of Magic. Although the timely arrival of members of the Order of the Phoenix saves the teenagers' lives, Sirius Black is killed in the conflict.