Hermione Granger is crucial to Harry and Ron in their successful mission to solve the mystery of the Chamber of Secrets. Hermione is revived after Harry kills the basilisk, but she is distraught to learn that all end-of-year exams have been cancelled as a school treat. Hermione buys a cat named Crookshanks, who takes to chasing Ron's pet rat, Scabbers. Before the start of term, Professor McGonagall secretly gives Hermione a Time-Turner, a device which enables her to go back in time and handle her heavy class schedule, though this is not revealed until the penultimate chapter. Much tension comes into play
Ministry of Magic of the Ministry of Magic. At the beginning of the series, it is headed by Amelia Bones, who is replaced by Pius Thicknesse after Voldemort murders her. Thicknesse is replaced by Yaxley in "Harry Potter and the Deathly Hallows" after Voldemort has Thicknesse appointed the puppet Minister for his regime. Bartemius Crouch Sr. once headed the department, prior to the first book. By the events of "Cursed Child", Harry Potter has become its head. According to Rowling, this is the department that Hermione Granger joins, after the events of the seventh book, transferring from the Department for the Regulation and