A scientist spends his life breeding creatures from the eggs of martian soil samples. When one of the 'Sandkings' nearly escapes from the secure facility, he is forced to shut down the whole project. But he refuses to accept the government's decision and sets up a private laboratory where he continues his experiments. As he continues his experiments, he begins to lose touch with reality, putting his experiments before his family. The 'Sandkings' have now built their own world and have claimed their first two victims. He soon realises how dangerous his experiments have become, but is he unable to stop it?