When charismatic terrorist Adem Qasim (Elyes Gabel) escapes from MI5 custody during a high profile handover, legendary operative Harry Pearce (Peter Firth), head of counter-terrorism, is blamed. Disgraced and forced to resign, Harry disappears without a trace. With MI5 on its knees in the wake of the Qasim debacle and facing controversial reform, disgraced former agent Will Holloway (Kit Harington
