It is based on the idea of the perfect crime: two strangers agree to exchange murders: one will be the murderer of the enemy of the other, which will give both of them, an indestructible alibi. Bruno alcoholic, with Oedipal issues and potential gay- is travelling on the same train that Guy ambitious and hard worker. Both start talking and the first forces the second to expose his weakness which is get rid of his unfaithful wife and that means an obstacle to marry the woman he loves. Bruno proposes a deal: he will kill the wife if Guy kills Brunoss father, who he hates. Guy refuses such a nonsense plan and forgets about it, but Bruno goes ahead with the plan, and informs his partner the crime, and demands him to honor his part. Bruno feels betrayed and harasses and frightens Guy with guilt and terror, whose mental health is gradually deteriorated by the pressure and implicates himself in Brunos horrific game.