After discovering conclusive evidence that someone has been shadowing the team and interfering in the past, Cutter’s suspicions fall on Lester and Jenny. He is determined to prove that one or the other of them - or perhaps both - is the traitor.

His plans are interrupted when an anomaly is detected and Lester’s worst nightmare comes to pass - a giant Colombian mammoth has appeared and is rampaging on a section of busy road in broad daylight, scattering cars and sending pedestrians running for their lives. Cutter and the team respond but Stephen is nowhere to be seen.

Dealing with the confused and angry mammoth requires every ounce of Cutter’s ingenuity but when the anomaly closes Cutter faces an even greater problem – how do you hide a mammoth? With the press about to break through the cordon Jenny has erected, Cutter formulates a new plan and with the help of Connor and Abby manages to trap the mammoth in the back of a lorry.

The team get away with it by the skin of their teeth, but Cutter is bewildered and angry with Stephen when he finally turns up, too late to be any real help and with no convincing explanation for his absence. To make matters worse Stephen has brought Helen with him. Cutter refuses to talk to either of them; instead he is determined to track down the enemy within. He sets a trap, letting only Connor and Abby in on his plan. They fake the appearance of an anomaly on the detector to see who will go to it first, knowing that whoever it is must be the traitor. The plan works, and reveals that the traitor is... Jenny.

Cutter is badly shaken by the revelation, but when he confronts her, she claims to have no idea what he is talking about - she received an anonymous text telling her to meet him there. The team discover that it is actually Leek who has set up the innocent Jenny. Not only that, but he has set a future predator loose at the ARC and is somehow controlling it to track down and kill Lester.

After a harrowing chase Lester manages to kill the predator and he tells his security force officers to find Leek and arrest him. Meanwhile Cutter and the team track down Caroline to a disused MOD base. Leek once again manages to fool them and he captures the team. When they come around they are shocked, not only to learn that Helen is in cahoots with Leek, but also he’s acquired a menagerie of creatures from different times.

Saturday 16 February 2008 7:15pm - 8:15pm on ITV1.