Hunter, head of the Section, requires the services of his best operative, David Callan. Callan had been 'retired' from the service due to his growing conscience, disrespect for orders, and concerns about the people he was ordered to eliminate. Callan now working as a bookkeeper, a job he despises, is offered to be reinstated into the Section if he kills Schneider, an international arms dealer.

Callan is lured into going to Berlin, where Hunter wants to use him as a sacrificial lamb to facilitate the planting of a British mole.

Callan and Meres must secure the safe of a ship that was sunk during World War Two. It contains a list of Third Reich collaborateurs and puppets. A survivor of the ship tries to stop them.

Callan debriefs a top enemy defector.