Gestapo chief Klaus Barbie once raged that he would give anything to capture the limping Canadian woman tormenting him in Lyon. But his most feared Allied spy was an American named Virginia Hall, a 35-year-old former journalist with a wooden leg she cheerfully called Cuthbert, and she was neither Canadian nor a traditional soldier.

Rejected by her own government's State Department because of her disability, Hall turned society's underestimation into her greatest weapon. She built resistance networks, orchestrated a daring jailbreak, hiked the freezing Pyrenees on her prosthetic, and commanded guerrilla armies, becoming the most highly decorated civilian woman of the Second World War while remaining largely unseen.

• How a hunting accident and a rigid State Department rule derailed her diplomatic dreams
• The brilliant tradecr ...