1949: William Catesby returns to London in disgrace, accused of murdering a ‘double-dipper’ the Americans believed to be one of their own. His left-wing sympathies have him singled out as a traitor.

Henry Bone throws him a lifeline, sending him to Marseille, ostensibly to report on dockers’ strikes and keep tabs on the errant wife of a British diplomat. But there’s a catch. For his cover story, he’s demobbed from the service and tricked out as a writer researching a book on the Resistance.

In Marseille, Catesby is caught in a deadly vice between the CIA and the mafia, who are colluding to fuel the war in Indochina. Swept eastwards to Laos himself, he remains uncertain of the true purpose behind his mission, though he has his suspicions: Bone has murder on his mind, and the target is a former comrade from Catesby’s SOE days. The question is, which one.