Sarah and Becker battle giant insects who have come through the rift at Johnson's H.Q. whilst Abby, Connor and Danny pursue Helen Cutter through the anomaly she has created. Her plan is to travel back to Africa in the year four million B.C. in order to stop the evolution of human life. With Connor injured Danny faces her alone but has an unexpected ally to help him save the world. Can he make it back to his own time before the anomaly closes?

Connor and Abby struggle with life in the Cretaceous Period, meanwhile the A.R.C. has been rebuilt and updated with two new members.

When Connor looks up old friend Duncan, he doesn't expect to find him obsessed with creature sightings. Warning him of the elusive dock creature, the pair track it down to the docks, only to find evidence of a fresh kill. With Abby and Matt arriving to help, they find the creature after a tense chase through a container yard. Will Connor's quick-thinking and bravery earn him back his place on the team?