Loner Sam's life is transformed when he comes into possession of a gun and starts to break the law. His ambitious policewoman sister Gina is paid to uphold it and makes it her mission to find the owner of the weapon. The family saga plays out against an inquiry into the shooting of a local businessman that raises questions for Sam and Gina about their father's murder when they were young children.
When Gina discovers a body on the beach, the victim’s boyfriend accuses a local businessman. Gina is distracted from the investigation by Sam’s return home from prison.
With the discovery of another body, the police connect the victims to a rugby club whose members were accused of rape years ago. Sam gets closer to his new boss, Dai.
Dai is rattled when his bike shop is broken into, but he won’t tell Sam what’s wrong. Gina and Luke investigate reports of a gunshot heard near one of Jeff’s businesses.
After his argument with Gina, Sam stays with his mother but still gets caught up in the feud between his caseworker, Caryn, and her husband, DI Morgan Riley-Gina’s boss.
Knowing he could be the next victim, Jeff’s son, Richie, offers to let the police use him as bait to draw out the murderer. Sam discovers something shocking about Caryn.
With Morgan missing, Caryn makes a police statement to Gina. Gina finds the killer’s address, but he’s moved on to a new target: Jeff.
