Professor Nick Cutter is investigating the sighting of a dinosaur, apparently. A species which has been extinct for 200 million years. With his team, they travel to the region where it was sighted to explain how it appeared. However, as they investigate the dinosaur, a weird creature seemed to be killing anything on its path.

In the London Underground, a cleaner is fatally bitten by a gigantic spider, and Nick Cutter's team investigate. In their search, they come across a maze of unused tunnels, leading to an even scarier event.

Swimming pools, inner-city reservoirs, and flooded cellars in suburban homes are being overtaken with prehistoric reptiles, which have all come through the space-time anomalies. The gang go to investigate, but Nick is more concerned with finding his wife.

Nick discovers that a group of dodos are carrying a deadly ancient parasite that could have devastating consequences for the human population. Meanwhile, Helen is back in the 21st century, and being interviewed by the Home Office, although she isn't being as cooperative as they hoped.

A prehistoric winged reptile arrives through an aerial time rift on a golf course. Nick goes to investigate, but he ends up trapped in a house with Claudia. Elsewhere, Connor loses Rex, much to Abby's anger.

Helen returns and claims that a predator from the future is behind a number of disappearances, so Helen and her estranged husband join together on a desperate race through time to prevent further attacks.