ON THE evening of 29 May 1973, Leesa Jo Shaner drives to the airport in Tucson, Arizona, to pick up her husband, Gary. He's returning from a tour of duty with the US Air Force in Okinawa. With his flight due to arrive at 10.15 pm, Leesa sets out in her father's car at 9.25. At 10.30, Gary phones home from the airport to say she hasn't arrived.

Leesa's father, Jim Miller, figures she's had car trouble. So he drives to the airport, keeping an eye out for her along the way. Once there, he searches everywhere, even the women's washrooms, and asks every staff member in the terminal if they've seen her. No one has.

About half an hour later, father and husband find her car in the parking lot. One window is partly rolled down, and Leesa's open purse is on the back seat. Her money is untouched. ...