Field Grey: Bernie Gunther Thriller 7 by Philip Kerr
It's 1954 and Bernie has tired of his increasingly dangerous work spying on Meyer Lansky for Cuban Intelligence. He secretly buys a boat and sails to Florida, where he's arrested, sent back to Cuba and imprisoned in the Isle of Pines. There he meets Castro, and a French intelligence officer, Thibaud, who liaises between the CIA and French intelligence. Exhaustively questioned by Thibaud, Bernie finds himself flown back to Berlin and another prison cell with a proposition: work for the French or hang for murder.
Bernie's job is simple: to meet and greet POWs returning from Germany. One of these is Edgard de Boudel, a French war criminal and member of the French SS, who has been posing as a German Wehrmacht officer. The French are anxious to catch up with this man and deal with him in their own ruthless way. But Bernie's past as a German POW in Russia is about to catch up with him - in a way he could never have foreseen.