Film producer James Ballard and his wife, Catherine, are in an open marriage. The couple engage in various infidelities, but between them have only unenthusiastic sex. Their arousal is heightened by discussing the intimate details of their extramarital sex. While driving home from work late one night, Ballard's car collides head-on with another, killing its male passenger. While trapped in the fused wreckage, the driver, Dr. Helen Remington, wife of the killed passenger, exposes a breast to Ballard when she pulls off the shoulder harness of her seat belt. While recovering, Ballard meets Remington again, as well as a man named Vaughan, who takes a keen interest in the brace holding Ballard's shattered leg together and photographs it. While leaving the hospital, Remington and Ballard begin an affair, one primarily fueled by their shared experience of the car crash (not only do all of their sexual assignations take place in cars, all of Remington's off-screen sexual encounters take place in cars as well). In an attempt to make some sense of why they are so aroused by their car wreck, they go to see one of Vaughan's cult meetings/performance pieces, an actual recreation of the car crash that killed James Dean with authentic cars and stunt drivers. When Transport Ministry officials break up the event Ballard flees with Remington and Vaughan.