Within the Hollow Crown

Lucius failed at the Ministry, and Draco is sent to Hogwarts with a cryptic warning that he will be tasked with an unknown mission. He expects to spend his sixth year on prefect rounds with Pansy and finally beating Potter on the Quidditch Pitch. He never expected his new roommate to be Voldemort himself, or that Voldemort's obsession with trophies would apply to him.