When Wyoming ranchwoman Ashley Russell sees a human-appearing man step out of a shimmering atmospheric anomaly in her horse pasture, and learns that he is a defenseless, courageous, but terror-stricken android who accidentally traveled four hundred years back in time in an escape pod released by a doomed military space ship, she offers to conceal his nature, and let him live in her home, purely out of the kindness so deeply a part of her. Belatedly, she discovers that not only is the manufactured person to whom she gives the name Jason Jones capable of sexual intercourse, he also sees the sixty-year-old widow as attractive. Ashley takes Jason as her lover.
When an old friend of hers visits--a helicopter pilot named Charlie Hogan--Ashley greets him warmly. Jason experiences jealousy, an emotion new to him, but being incapable of hating a human being, he reacts by agitatedly expressing a wish not to become a burden to his benefactor. On hearing that she thinks of Charlie as a brother, Jason grows greatly relieved.
Informed by the patently worried android that a second escape pod will shortly descend, and that the occupant, Lieutenant Commander Mina Baxter, will track him down so as to destroy him, Ashley implements a strategy designed to protect her vulnerable lover and herself from an enemy the self-reliant descendant of pioneers regards as a murderous interloper in her life.
Faced with a series of daunting challenges, the fearless ranchwoman and the selfless android draw on their ample reserves of courage and cunning so as to survive.