Season 4

Dublin gang boss Nidge has been blooded and has proved his mettle. He has killed friend and foe to become King. But the throne is a dark and lonely place.

Nidge coerces his dentist into cooperating with him, unaware that Detective Inspector Moynihan is setting up a complex undercover operation to track and ultimately bring him down.

Fran, still afraid that he could go down for the tiger kidnapping, lashes out looking for someone to blame. Resulting in a serious challenge to Nidge's authority.

Moynihan's surveillance operation closes in on Nidge and Andrew's dummy run bringing in a shipment of mixing agent, while Fran plots a gruesome revenge.

Nidge's preparations for the import operation are disturbed by an unwelcome encounter with a ghost from his past, and Nidge will do anything to prevent a terrible truth getting out. Isolated and increasingly paranoid, Nidge finds solace in his relationship with Janet and fails to notice that Moynihan and his undercover team are closing in on one of the conspirators...

As the shipment of drugs arrives at Dublin port, the deadly game of cat and mouse between Nidge and Moynihan reaches its climax.