"The Order of the Phoenix" is the fifth book in the Harry Potter series by J.K. Rowling. It follows Harry Potter as he returns to Hogwarts School of Witchcraft and Wizardry for his fifth year, facing challenges from both the school administration and the dark forces of Lord Voldemort. The story explores themes of friendship, loyalty, and the struggle against oppression. In this installment, Harry and his friends form a secret group called Dumbledore's Army to prepare for the looming threat of Voldemort. The book also delves into the complexities of Harry's relationships and the impact of the Ministry of Magic's denial regarding the return of Voldemort.