A small French resistance group came to London after the war to avenge the death of their leader, betrayed to the Gestapo by one of their own members. But the traitor, Mallory, proved more than a match for them, and two corpses later, the remaining three called in outside help. They chose Martin Corridon, an ex-commando, who accepted the job and planned a neat double-cross of his own once he had the money. But it didn't quite work out that way: Corridon found himself trailing Mallory from the dens of Soho to the wilds of a remote Scottish island...