A routine raid led by Emer Berry, a detective in the Irish Criminal Assets Bureau, reveals that a small-time drug dealer has been receiving substantial funding from a seemingly untraceable source - not in cash, but in rough diamonds.

Darren's killers escape, and Christian tells Emer a further bomb is expected; in Antwerp, billionaire Richard Melnick shows the site for his new European headquarters to his son James, Bibi's husband; the CAB team link Darren to Fionn Brannigan.

Emer has Fionn Brannigan firmly in her sights; as the net closes in, Bibi feels the pressure, especially when her wayward brother reaches out for help.

Emer's in Antwerp to help search for Fionn Brannigan, but the discovery of a body and a forensics breakthrough changes everything.

While the team follow the money trail in Ireland, Emer and Christian discover the real identity of the bombers. An unexpected source provides the investigation with invaluable information.

With Bibi now in custody, Emer and Christian face a desperate race against time to stop the final bombing and uncover who was really behind the terrorist campaign.