Four couples discover how far each will go to escape the boredom and routine of their lives.Set in a suburb of Chicago in the 1950s, the story centers around four married couples. The men play golf together at the local country club, and the women play bridge every week. One man reads about the "key party" game in a magazine and shares it with his friends. The idea is that the women put their house keys in a hat, and the men select a key at random; the key each man draws determines which woman he'll have sex with that night.One night while all four couples are together celebrating one couple's anniversary and a lot of drinking is going on, the man suggests that they play the game. Surprisingly, the women agree. No one sleeps with anyone else's wife, but the whole incident causes a lot of friction in the group. Somehow, word gets out in the community about the key party, and all four couples are shunned.