MI6's Head of Station in Turkey is killed in a mysterious plane crash. Amelia Levene, chief of the Secret Intelligence Service, wants the incident investigated; quickly and quietly. The only man she can trust is Thomas Kell, a disgraced spy searching for redemption. Kell's search for the mole takes him from London, to Greece, and into Eastern Europe. But when Kell is betrayed by those closest to him, the stakes become personal.