A year after leaving Dublin in a hurry, Darren Treacy returns, but the killing of one of the members of his old gang has far-reaching consequences for Darren's friends and family as suspicion runs rife and thoughts turn to revenge.

Darren is tracking Jimmy Byrne, the chief suspect in the gangland killing, but soon finds himself slipping back into working for gangland boss John Boy.

Tensions and suspicions escalate within the gang as Darren closes in on the truth and faces up to his feelings for Rosie.

Nidge and Trish's wedding day arrives; John Boy and Hughie begin a recruiting campaign in anticipation of the looming gang war, while Darren struggles to protect Mary and the children from the escalating conflict.

John Boy is haunted by the death of his brother in the form of a mysterious ghostly figure he keeps seeing on the security CCTV system at his apartment stronghold.

John Boy blames Stumpy when a drug mixing factory is busted by the Gardai; Darren, desperate to get out of the game, robs an ATM and makes a down payment to John Boy against the debt he owes.