Gia Carangi travels to New York City with dreams of becoming a fashion model. Within minutes of arriving, she meets Wilhelmina Cooper, a wise and high-powered agent who takes Gia under her wing. With Cooper's help and her own natural instincts, Gia quickly shoots to the top of the modeling world. When Cooper dies of lung cancer, however, Gia turns to drugs – and both she and her career begin to spiral out of control.

In Los Angeles, Max Carlyle makes a good living directing commercials and has a happy home life with his wife, Mimi, and two children. When Carlyle travels to New York City to visit his friend Charlie, who has been diagnosed with AIDS, he has repeat run-ins with a beautiful woman, Karen, and eventually sleeps with her. Though he goes home the next day and doesn't return until a year later, Carlyle's infidelity still lingers.