Character from harry-potter-half-blood-prince by
The Half-Blood Prince — finally teaching Defense Against the Dark Arts, bound by an Unbreakable Vow, and destined to kill the only person who ever trusted him completely.
Snape gets the Defense Against the Dark Arts position at last. He teaches with cold competence. He made the Unbreakable Vow with Narcissa — to protect Draco, to complete Draco's task if the boy cannot. Dumbledore asked him to do this. Dumbledore is dying anyway and wants Draco's soul unscarred and wants the Elder Wand's allegiance to pass to someone who won't misuse it. On the Astronomy Tower, Dumbledore says 'Severus, please' and Snape kills him with the Killing Curse. He flees Hogwarts, fights Harry in the grounds, blocks every curse Harry throws, screams 'I am the Half-Blood Prince' when Harry uses his own spell against him, and disappears into the darkness. He was the Half-Blood Prince — the brilliant, bitter, lonely half-blood student whose textbook Harry has been following all year. Every improvement. Every dark spell. Every annotation in the margins. Snape's.
Sallow-skinned, hooked nose, greasy black hair, black robes. The same as always, but this year he watches Draco with an intensity that isn't just suspicion.
Also known as: Snape, Severus, Severus Snape, The Half-Blood Prince