Restless and unhappy, two couples get caught up in infidelity and deception. Barry is a sullen businessman married to Mary, a writer who is unsatisfied with their relationship. Mary begins an affair with Jerry, a smug theater professor and husband of her friend, Terri, who is also a writer. Adding to the adulterous mix are Cary, a callous doctor, and Cheri, an art-gallery assistant.
Dr. Archie Bollen is having a midlife crisis. He's just divorced his wife and is establishing a new life for himself. One night, he catches the eye of Petulia Danner, a charming, free-spirited young woman. Petulia's vibrant personality hides her fear of her abusive husband, David, whose father is a powerful society figure. As Petulia and Archie's feelings for each other grow, they must decide what it is they truly want.
A married woman and her lover plot to kill her husband to make off with the insurance money. However, their attempt to murder him using poisonous fish toxins backfires in surprising ways.
After returning to Los Angeles from a group therapy session, documentary filmmaker Bob Sanders and his wife, Carol, find themselves becoming vigilante couples counselors, offering unsolicited advice to their best friends, Ted and Alice Henderson. Not wanting to be rude, the Hendersons play along, but some latent sexual tension among the four soon comes bubbling to the surface, and long-buried desires don't stay buried for long.