Johnny Nicholas had many faces. To some he was "Major John Nicholas," a downed black American pilot who parachuted into France on a secret intelligence mission. To others he was a key player in the French Resistance and a doctor who'd set up a practice in Paris as a cover for his clandestine activities. At a well built 6 feet, he was a bon vivant who loved the high life, and a film producer with a penchant for boldly thumbing his nose at the Nazis in World War II Paris. To Florence, his blonde girlfriend, he was an enigma who cheated on her; she betrayed him to her German handlers. Nicholas...