Even deadlier than terrorists . . . are the men trying to stop them.

People-smuggling, counterfeit currency and attempted murder. It's all in a day's work for undercover cop Dan 'Spider' Shepherd. But what starts as a run-of-the mill investigation quickly turns into a matter of life and death when he uncovers a terrorist cell on a mission of death and destruction. The target: hundreds of passengers on a cross-channel train deep below the English Channel.

With the clock ticking and the explosives primed, Shepherd and his colleagues have to decide just how far they are prepared to go to save innocent lives. And they realise that to avoid catastrophe, they have to be even more merciless than the terrorists.