Roy Masterson is an American from the Twenty-first century, conscripted into a temporal conflict by the ubiquitous Genitor. His consciousness is placed in a synthetic clone body of an alien humanoid species called the Dionan. Trained as a servitor on the planet Cassida, Masterson struggled to discover his identity and purpose before being deployed to the planet Mundus. He soon comes to realize that Mundus is his own world of Earth, but in the distant past.