With the exposure of a major drug trafficking ring operating in Aberdeen, Scotland Yard Chief Inspector Conor McDermott and Inspector Andrew Fletcher uncover clues leading them to a police informant providing a Glasgow crime syndicate with information to manipulate the trial of their suspect. As they gather clues to the drug trafficking ring, a mysterious hit-man exacts his own brand of justice to preserve the identity of his employer in the court case, leaving the inspectors caught in the cross-fire of learning about the source funding the drugs and the ship captains transporting them. Fearing for his well-being and that of his crew, one of the ship captains turns to an old adversary for help.