Eddie Chapman was a small-time thief in England in the 1930s. He was eventually arrested on the Island of Jersey in the Channel Islands and imprisoned there, about 6 months before Nazi Germany seized and occupied the island. In an effort to gain his freedom he went to his German guards and said that he would be willing to work as a spy for Germany, touting his previous experience with explosives, his undoubted skill as a con-artist, and his ability to break and enter. After much discussion and many interrogations he was recruited and trained by the Abwehr, and was eventually assigned a significant sabotage mission. Immediately on parachuting back into England he contacted MI5 and offered his services as a double agent, eventually designated agent ZigZag.
This is a genuinely gripping story. It reads at times like a novel, driven forward by the complex and devious character of Eddie Chapman. He was brilliant, restless, and driven. While imprisoned on Jersey he taught himself French and a bit of German. He quickly became fluent in French, as he quickly became adept at the spycraft taught him by both the Abwehr and MI5. He withstood the stress of being a double-agent, volunteering to return to France and to his Abwehr controller after being successfully run as a double agent in Britain for 4 months.