Los Angeles detective Jake Gittes is hired by a woman claiming to be a Mrs. Mulwray to spy on her husband. Shortly after Gittes is hired, the real Mrs. Mulwray appears in his office threatening to sue if he doesn't drop the case immediately. Gittes pursues the case anyway, slowly uncovering a vast conspiracy centering on water management, state and municipal corruption, land use and real estate, and involving at least one murder.