A murder investigation is launched in the steel town of Port Talbot when the dead body of local businessman Stevie Rose is discovered in the town's marina. Ambitious policewoman Gina spies an opportunity to win promotion by helping to track down Stevie's murderer. Unbeknown to Gina, her brother Sam is befriended by a new neighbour with a favour to ask and he finds himself in possession of a gun.

Stevie Rose's widow Patricia astounds the police by offering a reward for information that might lead to the discovery of her husband's murderer. Gina becomes convinced that Sam's new neighbours have something to hide and Sam finds it increasingly difficult to live with the gun. Gina comes across a face from the past whilst investigating Stevie's murder and Sam loses someone very important.

Sam is threatened by a colleague after he's wrongly accused of stealing from the warehouse. Cai pressures Sam into compensating him for his sacking and the two make plans to stage a robbery. Gina is formally invited to join the murder investigation and the discovery of the body of one of Stevie's former employees throws new light on Stevie's business affairs. Sam and Cai stage their robbery and Cai is left reeling.

Cai is eager to stage another robbery and Sam agrees to target Ray's builders' yard following an argument with his stepfather. The robbery goes wrong when a security guard interrupts them and Cai acts without thinking. The incident frightens Cai and he starts behaving impetuously. Sam is horrified to realise Cai's behaviour has attracted the interest of the police and there are consequences for the pair of them. Gina is angry when she's sent home from work by Layla and Patricia pressurises Gina to give her information about the investigation into Stevie's murder.

Gina comes across information that casts fresh light on her father's death and the discovery leads to an honest conversation with Linda about the past. Sam meets a woman called Ela who turns his life upside down.

While staying at a hotel Sam and Ela take advantage of another guest with heartbreaking consequences for Sam. Gina searches for more information about her father's death.