In this third series, explosives officer Lana Washington and her team are called to investigate a bomb threat that soon reveals itself to be the start of a sinister vendetta. Someone is targeting individuals, and demanding revenge. Working alongside the Police Counterterrorism Unit, the Bomb Disposal Squad race against time to find the bomber before they claim their next victim.

Lana is back from secondment in Estonia, training Ukrainian bomb disposal teams, but has not yet returned to active duty. She is giving a routine talk to security officers from major financial institutions about the issues surrounding bomb centred terrorism, when there is a bomb attack in the heart of the city. Lana is closest to the incident, but is she ready to take it on?