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
Hermione Granger is the best student in Harry's year and is repeatedly the first student to master any spell or charm introduced in classes and even from more advanced years, as evidenced when she is able to conjure a Protean Charm on the D.A.'s fake Galleon coins, which is actually a N.E.W.T. level charm. She is also the first one to be able to cast non-verbal spells. Hermione is a competent duellist - Rowling has stated that while during the first three books Hermione would have beaten Harry in a magical duel, by the fourth book Harry had become so good at