Sitting on a bus, two men discuss a project to the interest of a fellow passenger. Leaving the bus the two men are followed and then persuaded to tend to the sick crew of an alien craft and also to affect repairs. They are not allowed to leave and find themselves in an alien zoo. Join them as they form partnerships with two women from another planet and plot their escape and the destruction of their captors. They must then decide whether to stay with locals who thank them for deliverance, or try to find a way home.