In darkest rural Ireland, ex-boxer Douglas 'Arm' Armstrong has become the feared enforcer for the drug-dealing Devers family, whilst also trying to be a good father to his autistic five-year-old son, Jack. Torn between these two families, Arm's loyalties are truly tested when he is asked to kill for the first time.
The story follows fisherman Ed Collier, who is highly protective over his family, which includes wife Claire and daughter Abbie. However, when a rich young man by the name of Ryan Wilson starts to take an interest in his daughter, Ed feels her becoming increasingly distant and fears he may lose her for good.
Two estranged cousins who never knew each other try to make amends for many generations of family dispute.
