Donna, a dental hygienist, is stuck in an unsatisfying marriage with her husband, Jared, who claims he works in an airport. After a mysterious work accident, Jared's eyes gleam, and he acts differently than normal, making love to Donna with an unusual passion. Donna learns that the improved Jared is not actually her husband, but an alien visitor named Glreerak who is co-habiting Jared's body as part of an experimental exchange program.

Donna is stunned that Jared hid his true occupation from her, and starts to prefer spending time with Glreerak, even taking him on a vacation that she hides from Jared. When Jared discovers that Glreerak has been taking over his body and having sex with Donna without his permission -- and that Donna was encouraging it -- he terminates the experiment and leaves her, never to be seen again.