Mit : Joe Cole, Alexandra Roach, Kim Chapman,

When they realise that one of the passengers may be armed and operating in league with the hackers, Joe desperately tries to work out who he can trust. Abby decides to turn the tables on the driver by making a last-minute decision to take the train off the mainline. As Joe closes in on the enemy within and Abby manages to catch the sleeper in her trap, will the police be able to get there in time?