During a handover to the head of counter-terrorism of MI5, Harry Pearce, a terrorist escapes custody. When Harry disappears soon after, his protégé is tasked with finding out what happened as an impending attack on London looms, and eventually uncovers a deadly conspiracy.

• Creative England
• BBC Film
• Peter Firth
• Kit Harington
• Elyes Gabel
• Jennifer Ehle
• Tim McInnerny
• Tuppence Middleton
• Eleanor Matsuura
• David Harewood