A Strange Couple (1976)

Following a faint trail of crumbs and half-baked leads, an inquisitive private detective is entrusted with exposing the truth behind the adulterous wife of a powerful and extremely wealthy man. However, as his investigation fails to produce results, he finds himself entangled in a dangerous game of deceit and lust, as the seductive woman will do everything in her power to escape from her murderous husband's clutches. Is there a future for the strange couple?