TAPA DURA , LIBRO USADO, RECUERDA QUE EL 10% DE ESTA VENTA COLABORA CON FUNDACIONES QUE FOMENTAN LA LECTURA EN ZONAS VULNERABLES. This is the autobiography of John Cairncross, the man who gave the Russians the decrypt of the ENIGMA code, thus enabling them to win the battle of Kursk and turning the war against the Germans. It reveals why he turned to espionage, what data he passed on and how MI5 finally tracked him down.