When Los Angeles private eye J.J. Jake Gittes (Jack Nicholson) is hired by Evelyn Mulwray to investigate her husband's activities, he believes it's a routine infidelity case. Jake's investigation soon becomes anything but routine when he meets the real Mrs. Mulwray (Faye Dunaway) and realizes he was hired by an imposter. Mr. Mulwray's sudden death sets Gittes on a tangled trail of corruption, deceit and sinister family secrets as Evelyn's father (John Huston) becomes a suspect in the case.