House: Season 4, Episode 15

4 - 15: House's Head

House finds himself dazed, confused and covered in blood after surviving a bus accident that left dozens seriously injured. Unable to clearly recall the events leading up to the crash due to his head injuries, House is convinced through his flashbacks a fellow bus passenger is exhibiting signs of a deadly illness prior to the crash. Much to the team's dismay, House pushes through the pain of his injuries, desperate to piece together the fragments of his shattered memory in order to save someone who might not even know he could be dying. And once he learns the truth, he and his team are left shellshocked when it's discovered that Amber Volakis, Wilson's girlfriend is the one who's dying.