The time is 1977 and the Voyager II has just been launched into outer space. This act has invited all forms of alien life in the universe to visit our planet.
Jenny Hayden (Karen Allen) is a young woman who is still struggling with coping with the death of her much loved husband.
However, one of these uninvited aliens has decided to take on the form of Jenny's husband in order to pass unnoticed in our world. Now he has approached Jenny she is understandably confused, if not terrified of the prospect of her husband returning form the grave.
Now the alien, known as StarMan (Jeff Bridges) kidnaps Jenny in order to get across country from Wisconsin to Arizona where his space ship awaits, but the government's knowledge of this puts endless obstacles in their way.
As he learns how to become more human, StarMan begins to take on more and more qualities of Jenny's husband, which inevitably plays with her mind, and on her grief, drawing her ever closer.