After almost losing everything to D.I. Moynihan’s sting operation, Nidge travels to Spain to negotiate with a wholesale supplier for a new drugs shipment. Meanwhile, Patrick has returned to Dublin to exact revenge, and tensions between Fran and Nidge reach boiling point.

With Pauley’s help, Nidge is back in business and arrangements are made for the first shipment under the new deal. Meanwhile Moynihan wrestles with a labyrinthine Garda bureaucracy.

Fran is banged up in prison but he and Nidge both still conspire to have each other killed, while Siobhan finds her dangerous drug fuelled double life is spiralling out of control.

Nidge uses Scotty as a driver on a new job, while Siobhan learns Tommy will soon wake from his coma and finds herself caught between her quest for revenge and her love for Pauley.

In the aftermath of Pauley’s death Siobhan must face her most terrifying opponent yet as Terence May flies in from Spain to lay his nephew to rest—and to find the truth.

Nidge is summoned back to Spain, where Terence demands a terrible price for his continued support, while Siobhan and Moynihan reach an unholy deal of their own.