From 1991 to 1992 Quirinus' occupation was Defense Against the Dark Arts Professor for Hogwarts, in
Hogwarts.
- Occupation Notes
It is revealed that, during his travels, Quirrell had met a barely-alive Voldemort. Voldemort, seeking to restore his physical form, entered Quirrell as a host body, using him in a plan to steal the Philosopher's Stone from vault 713 in Gringotts Bank, where it had been deposited for safekeeping by Albus Dumbledore. Fortunately, Hagrid had removed the Stone from the vault earlier that same day to take it to Hogwarts.
To conceal the fact that Lord Voldemort's face was on the back of his head, Quirrell decided to wear the turban, hiding its purpose with a story that it had been given to him by an African prince as a thank-you for getting rid of a troublesome zombie. In order to keep Voldemort alive, he started killing unicorns in the Forbidden Forest and drinking their blood.
On Halloween Quirrell let the troll in as a diversion, and went to the third-floor corridor where the Stone was now hidden. Severus Snape, who already suspected Quirrell, went to the third floor in order to stop him. Snape was bitten by Fluffy.
In order to figure out how to get past Fluffy, Quirrell got Hagrid drunk, and gave him a dragon's egg, something Hagrid had always wanted. Quirrell sent a letter to Dumbledore, telling him to go to the Ministry of Magic; Quirrell took advantage of his absence to try to reach the Stone, and was pursued - unwittingly, as they thought they were pursuing Snape - by Harry, Ron and Hermione.
During Harry's final encounter with him - at which Voldemort reveals himself on the back of Quirrell's head and speaks directly to Harry - Quirrell is killed. Due to the lingering protection from Lily Potter's sacrifice of love for her son, Quirrell is unable to touch Harry without suffering extreme pain. Although Harry is rendered unconscious, he holds off Quirrell long enough for aid to arrive, at which point Voldemort flees in his spirit form. His departure causes Quirrell's death, hence Dumbledore's comment that Voldemort is as merciless to his followers as to his enemies.
Prof Quirinus Quirrell 
