Harry Potter: The Order of the Phoenix & The Half-Blood Prince

In the Order of the Phoenix, with their warning about Lord Voldemort's return scoffed at, Harry and Dumbledore are targeted by the Wizard authorities as an authoritarian bureaucrat slowly seizes power at Hogwarts. In the Half-Blood Prince, as Harry Potter begins his 6th year at Hogwarts School of Witchcraft and Wizardry, he discovers an old book marked mysteriously "This book is the property of the Half-Blood Prince" and begins to learn more about Lord Voldemort's dark past.