The Nazi juggernaut rolls across Europe. Refugees begin to pour out of the conquered lands and soon Lisbon becomes the last hope for escape to the new world. Anticipating the fall of France, the American ambassador decides to establish a clandestine network for intelligence work and covert operations. His choice to lead this group is the remarkable Joe McQueen, a former Navy Commander and soldier of fortune who now operates a cargo service out of Lisbon. Flying his modified Grumman Goose and taking on dangerous assignments other pilots only dream of, he has built a reputation as the toughest and luckiest pilot in Europe and a man with nerves of steel. In South of Sahara, McQueen is recruited by the Ambassador to rescue an English archaeologist lost in the desert who may have stumbled onto something vital to the German war effort and which must not fall into their hands.