On June 7th, 1927, Jack answered his telephone. "Jack? This is George Marion . . . from the 24th Aero Squadron in France . . . I chased the kraut off your tail the day you crashed at Souilly Aerodrome during the War." Duty-bound to help the man who saved his life, Jack agreed to the fighter pilot's urgent plea and found himself embroiled in a fifty year-old mystery in ancient Indian ruins in the New Mexico desert of Chaco Canyon. Myths and facts interweave in a blanket of suspense and intrigue while Jack and his friends struggle to pierce their war-time comrade's deceits to learn the true purpose of their mission - and survive. Obligation Flight is the second in a series of Jack Riley mysteries. In Jack's first adventure, The Babylon Hoard, he solved the 1,000 year old riddle of The Key - hidden by an ancient Babylonian king, found by Crusaders, brought to America by Maryland Colonists - and finally deciphered by Jack and his friends.