There is no doubt about Jimmy Picard's (BENICIO DEL TORO) mental state: schizophrenic. When the war veteran, a Native American of the Blackfoot tribe, returns to Kansas in 1948, he is plagued by dizziness, temporary blindness and hearing loss, symptoms that doctors interpret as signs of a multiple personality. Jimmy is ready to give himself up as incurable when an eccentric personality enters his life. Jewish psychiatrist Georges Devereux (MATHIEU AMALRIC) manages to get the closed-off Indian to talk, but will he get to the bottom of Cause?