Trevor Reznik (Christian Bale) hasn't slept in a year. The shocking deterioration of his physical and mental health has made his every waking moment an unrelenting state of confusion, paranoia, guilt, anxiety and terror. His only solace from this living nightmare comes from an affectionate prostitute (Jennifer Jason Leigh). When cryptic notes turn up mysteriously in his apartment and when hallucinations of a co-worker that no one else sees causes a gruesome machine shop injury, he embarks on a journey to find out whether there is an elaborate plot to drive him mad or his fatigue has simply robbed him of reason. The more he learns, the less he wants to know.