Bang is the story of a brother, a sister and a gun. 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. A crime drama about blood, love and human relationships set in the steel town of Port Talbot.