Factory machinist Trevor Reznik (Christian Bale) has not slept in a year, which has led to deterioration of his physical and mental health. His world becomes a living nightmare when cryptic notes turn up in his apartment and he has visions of a coworker no one else can see. Are these mysteries part of a plot to drive him mad? Or has fatigue simply robbed him of reason? Determined to find answers, he embarks on a journey of self-awareness -- yet the more he learns, the less he wants to know.