Turner and Doyle are running a top-secret department within the UK government called SF20. Their remit is to take down enemies of the state and to kill if necessary. If caught they will be disowned and deniable. A terrorist cell becomes operational in London. They explode bombs on the London Underground. Doyle's job is to find them and take them out. While tracking them down he uncovers a sub-plot to take out members of the Houses of parliament. Lord Turner is on the list. It's a race against time, who will get there first? Not helping is the rivalry between the CIA, MI5 and MI6.