Although Ellie, Maisie and Tom survive - the detonator malfunctions and the bomb fails to go off - it turns it was all a feint in any any event and the IRA's real target was the Secretary of State for Northern Ireland. Following an attack on an Army base, MI-5 initially suspect the IRA but later become convinced that it likely the work of Serbian terrorists who soon attack a highly secret munitions convoy. While Danny tries to find the source of information leaks about he convoy, Zoe goes undercover to get to know Radovan, a close family member of the suspected terrorist ringleader. They learn the terrorists are targeting the government's meeting of the national emergencies committee. The bombing incident creates a great deal of stress between Tom and Ellie who is not sure she wants to continue their relationship. A new recruit, Sam Buxton, joins the team.
—garykmcd