Poor Felix Ungar’s marriage is over, and he’s devastated. Half-hearted efforts to do away with himself are highly unsuccessful, and so, distraught, he shows up at his weekly poker game held at best friend Oscar Madison’s house. Feeling sympathetic, his buddy Oscar even offers him a home. But it’s not an easy transition for either man. Oscar, a certifiable slob whose apartment is overrun with dirty dishes, old food, trash, and scattered laundry, can’t abide the hypochondriac Felix’s compulsive need for order and cleanliness. Sparks fly; differences threaten to quickly upend the best friends’ relationship.