Book 5 | Ch:36 - The Only One He Ever Feared

SPOILERS:

Harry pursues Bellatrix enraged and learns he is incapable of performing the Unforgivable Curse. Voldemort appears but Dumbledore saves Harry from being killed. Fudge and other Ministry members witness Voldemort’s return, and Dumbledore reinstates himself as Headmaster of Hogwarts.