Harry Potter, now a fifth-year student at Hogwarts School of Witchcraft and Wizardry, struggles with a threatening teacher, problematic house elf, the dread of upcoming final exams, and haunting dreams that hint toward his mysterious past.

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 Voldemort's past.