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.

The truth about Paddy's night is out. Boxed into a corner Nidge contemplates a new life in Spain - but soon realises it's only a matter of time before Dano catches up with him.

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.

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.

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.

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.

As tensions come to a head the gang threatens to implode: Luke's obsession with Mary is becoming more dangerous, while Siobhan's panic attack at the airport could get Tommy killed. Paranoid John Boy finally tips over the edge of sanity when he finds Debbie taking heroin.

Darren is tracking Jimmy Byrne, the chief suspect in the gangland killing. But in the meantime he needs to work and he soon finds himself slipping back into working for gangland boss John Boy Power. In a world of paranoia and betrayal will Darren be able to keep his wits about him, kill Jimmy Byrne and find love again with Rosie?

Darren Tracey skipped Dublin when a gun was found in his house and he’s been living the past year in Spain, but he decides to risk it and come back to Dublin. He’s homesick and a party for his brother’s release from prison is the perfect excuse. It’s only for the weekend but sometimes life is full of surprises - especially if you and your friends are in gangland.

The crew are in festive spirits as Trish has the baby on Christmas Eve, while Rosie has come back to Dublin and Darren falls in love with her all over again. However the gang war is still raging, and John Boy orders Tommy – already caught between his friendship with Debbie and his worries about Siobhan’s money runs – to kill Fran. The hit goes wrong, and someone else becomes fatally caught up in the aftermath.

As both Dano and the Gardaí begin to put the puzzle together, what can Nidge do to stay ahead and stay alive?

When a container of drugs is busted at the docks, John Boy decides to double cross Fran on their deal. Fran retaliates against John Boy. John Boy is furious and orders Nidge to pipe bomb Fran's house leaving Fran determined that the escalating gang war will not end until he has revenge.

The gang come back from Nidge’s stag party in Prague to learn that Jimmy Byrne is back in town. His friends think Darren should kill him as soon as, but Darren’s not so sure. Tension mounts as Darren needs to make decisions not only about whether to follow through on his suspicions, but about what he should do about his feelings for childhood sweetheart Rosie. As Darren grows closer to uncovering the truth, tensions and suspicions rise among the gang. Darren in particular faces difficult decisions about his feelings for Rosie, his future and his loyalties.

As Nidge and Trish’s wedding day arrives, gangwar is breaking out. John Boy and Hughie generate new plans and new recruits. Who will be with them? Darren is worried about John Boy and Hughie’s volatility, not just for himself but for his sister Mary and the kids. Relations between John Boy and Darren come to a head. Darren decides that it is in everyone’s interest that he heads for London. Can he end the war before he leaves?

Nidge sets out to persuade Dano that he had nothing to do with his father's disappearance but a scapegoat must be found. Nidge turns to ever faithful Darren for help.