Although Los Angeles doctor Zack (Michael Ontkean) is happily married to television executive Claire (Kate Jackson), he finds himself struggling with his increasing attraction to other men. These feelings boil over when he meets a new patient, the openly gay and hedonistic Bart (Harry Hamlin), with whom he begins a tempestuous and emotionally draining affair. His infidelity throws Zack and Claire's marriage into turmoil at a time when they had been discussing starting a family.