While his wife (Anne Archer) and daughter are out of town, successful attorney Dan Gallagher (Michael Douglas) has a one-night stand with Alex Forrest (Glenn Close), the publishing executive he has just met. He has no idea what he's getting into. Immediately after the encounter, Dan wants to put the experience behind him, but Alex refuses to let go of their relationship. Driven to madness by his rejection, she turns to violently harassing both Dan and his family. This terrifying morality play, which takes the consequences of infidelity to new heights of horror, became one of 1987's biggest box-office successes.