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
Legal disputes over the Harry Potter series Legal disputes over the Harry Potter series Since first coming to wide notice in the late 1990s, the "Harry Potter" book series by J. K. Rowling has engendered a number of legal disputes. Rowling, her various publishers and Time Warner, the owner of the rights to the "Harry Potter" films, have taken numerous legal actions to protect their copyrights, and also have fielded accusations of copyright theft themselves. The worldwide popularity of the "Harry Potter" series has led to the appearance of a number of locally produced, unauthorised sequels and other derivative works, sparking efforts to ban or contain them.