During the five years from May 1940 to May 1945 several thousand Allied airmen, forced to abandon their aircraft behind enemy lines, evaded capture and reached freedom, by land, sea and air. The territory held by the Germans was immense - from Norway and Denmark in the north, through Holland, Belgium, Luxembourg to the south of France - and initially there was no organisation to help the men on the run. The first one to assist the evaders and escapers ('E & E' as the Americans called them) was the PAT line, along the Mediterranean coast to Perpignan and down the Spanish border; named after a naval officer Pat O' Leary, from 1942 it became the PAO line.Next was the Comet line, from Brussels to the Pyrenees. Thousands of brave people were to be involved for whom, if caught, the penalty was death. Theirs is a stirring and awe-inspiring story. Respected historian Oliver Clutton-Brock has researched in depth this secret world of evasion, uncovering some treachery and many hitherto unpublished details, operations and photos.