In a future of total ecological collapse, desperation and regret, time travel to an unspoiled prehistoric past is accidentally discovered by scientists at a particle accelerator in southern California. The government is immediately interested: maybe this will be their out. They decide to send two people back to investigate. One, Julie Pine, a paleontologist, and dedicated conservationist, at the Los Angeles County Museum of Natural History, and Detrich Jaqzen, a professional hit man, as her bodyguard. Problem is, Jaqzen is also a big-game hunting rogue who has designs on Julie, a married woman, and relishes a virgin, primeval world where he can sport hunt to his heart’s content. After the two fail to return in 30 days time the crew at the Institute learn of Jaqzen’s treachery. Subversively, they decide to send Julie’s husband, Tom, back to rescue her. But at the last minute government troops break in to stop the launching, shooting up the place. A man falls over the controls, changing them, and Tom is still sent, but now to a locality many hundreds of miles off target. He soon discovers that he will have to make his way down the length of wild, prehistoric California to find Julie. Yet, all his long journey Tom revels in a world of stunning beauty, ecological diversity – and mortal danger. A world that, from his Anthropocene point of view, he had no idea ever existed. At the end of it, though, he knows he will have to confront Jaqzen.