Dan (Michael Douglas) has a happy family that everyone envies. The relationship between him and his wife Beth (Anne Archer) is stable and long-lasting, and his daughter Ellen (Ellen Hamilton Latzen) is even more clever and lovely. By chance, not only was Dan obsessed or something, he actually had a dewy relationship with a woman named Alex (Glenn Close). After returning home to face his wife and children, Dan's heart was full of guilt. He secretly vowed that he would never let the betrayal happen again. Unfortunately, Alex did not agree with Dan's view. On the surface, she was a mature and stable intellectual, but in her bones, Alex had a paranoia and stubbornness beyond ordinary people. In order to satisfy her own desires, she constantly harassed Dan and his family. Soon, this harassment escalated into a crime. Facing the menacing Alex, what countermeasures would Dan choose to protect his family?