Hopelessness took him in its grip. He knew he was wandering in circles but he had ceased to care. All he wanted to do was drink. His skin began to smart. His feet were on fire... It's the Second World War and Biggles is in the desert, defending the vital air-route from the West coast of Africa to the Middle East. Urgent stores, dispatches and important officials and officers are regularly flown over this route, but lately a number of planes have unaccountably failed to arrive at their destinations. They've disappeared on route and Biggles is there to find out why - and stop it happening again.