Brian Freemantle: Time to Kill (2006)

From the Publisher:
Jack Mason, once Russia's most successful CIA embedded traitor, has spent the last fifteen years in a penitentiary planning his vengeance on the Russian defector who exposed him. Former KGB Colonel Dimitri Sobell has spent these fifteen years making a new and perfect life for himself in America. He's married Mason's ex-wife Ann, the woman for whom he defected from Russia's Washington embassy. And become the proud father of David. He has also acquired a new and permanent name, Daniel Slater. Until he gets an official letter advising him of the man's impending release, he'd virtually forgotten Jack Mason. But Mason hasn't forgotten; he has trained himself to the peak of physical, assassin-ready fitness. And become an expert computer hacker. When these two brilliant intelligence professionals are pitted against each other in a private, revenge-fuelled confrontation, only one outcome is possible - the death of whoever makes the one fatal mistake.

Brian Freemantle: Time to Kill. Severn House, ISBN: 0727864467 (October, 2006), 281 p., £18.99.