With two incidents appearing to be connected, Counter Terrorism police work to establish a link between the two victims – a retiree and a university lecturer. As the investigation continues, the team grow suspicious that they aren't being told the whole truth, and an intervention from DS Helen Morgan backfires, leaving the unit at a loss.

All hope looks lost for the remaining missing person, until a new lead emerges. With Lana now known to the bomber, she has to work harder than ever to avoid falling into his traps, pushing her to breaking point.