Photo-journalist Steve Blake (Douglas Hodge) is the only witness to a horrific car accident in which the driver is incinerated in a gigantic fireball. Yet the next day, Blake finds the same man alive and well. Blake discovers that this is not the only case of apparent death and resurrection - all investigated by Chief Superintendent Philip Gates (Leslie Grantham) and all somehow linked to the drowned village of Sweethope. Blake becomes convinced that the Sweethope survivors are taking over the country in an invisible alien invasion. The tense drama races from intriguing mystery to gripping sci-fi thriller as Blake finds himself embroiled in a global conspiracy too terrible to consider and possibly too powerful to stop.