A man at a local swimming pool is killed by a Cretaceous marine reptile, a mosasaur when an anomaly appears there. But when the anomaly disappears and reopens several miles away in a reservoir, Nick Cutter (Douglas Henshall) realises that the anomalies have the ability to move, and his theory is confirmed when the anomaly opens for a third time in a residential basement, where a plumber is attacked by a Hesperornis. When the team find proof that Cutter's wife, Helen (Juliet Aubrey), is alive in the past, Cutter is ordered through the anomaly to find and bring her back.
