George, a professor at a small college, and his wife, Martha, have just returned home, drunk from a Saturday night party. Martha announces, amidst general profanity, that she has invited a young couple—an opportunistic new professor at the college and his shatteringly naïve new bride—to stop by for a nightcap. When they arrive the charade begins. The drinks flow and suddenly inhibitions melt. It becomes clear that Martha is determined to seduce the young professor, and George couldn't care less. But underneath the edgy banter, which is crossfired between both couples, lurks an undercurrent of tragedy and despair. George and Martha's inhuman bitterness toward one another is provoked by the enormous personal sadness that they have pledged to keep to themselves: a secret that has seemingly been the foundation for their relationship. In the end, the mystery in which the distressed George and Martha have taken refuge is exposed, once and for all revealing the degrading mess they have made of their lives.