The Traitor by Guy Walters
It is 1943. British SOE agent Captain John Lockhart is in Crete, fighting with the Resistance. Captured by the Germans, Lockhart faces a stark choice, between death and betrayal of his country. Concealing his true motives, Lockhart makes a bargain: in return for the life of his imprisoned wife, he will work with the Germans. When his mission is revealed, Lockhart is stunned. He is to lead a unit of the Waffen SS made up of British fascists and renegades culled from POW camps: the British Free Corps. Lockhart takes command, but he has an audacious plan to free his wife and other innocent victims of the war - whatever the personal cost.