Explosives Officers Lana Washington and Joel Nutkins are called out to investigate a potential bomb factory in a London housing estate, but there's no sign of the bomb makers.
As the bombing campaign intensifies, so do inter-community tensions as the far-right group English Flag take to the streets to blame Islamists for the attack.
A far-right group called the Crusaders claim responsibility for the mosque attack. Lana finds a forensic link between the bomb at the mosque and the one at Westhaven - were they both bombed by the same person?
Lana struggles to come to terms with her personal loss, and her failure to prevent the explosion. Meanwhile, Counter Terrorism officers identify the bomber and launch a massive manhunt.
The EXPO team are stretched to breaking point dealing with a complicated device planted at the Campaign HQ of the Progressive Alliance. Lana tells Karl she wants to break up.