A surgeon is murdered in mid-air with only his fellow airplane passengers as possible suspects in this classic closed circle mystery set in the age of early aviation.

1935: A surgeon, the appropriately named Dr. Cutter, is preparing to fly cross-country in a two-propeller plane to perform a life-and-death surgery on his brother, the Secretary of State. Just before boarding, he receives an anonymous note that says, You will die April 13th at Noon exactly Central Time. It seems to be an absurd threat because he is scheduled to be in mid-air in the company of a small number of passengers at that hour.

Of course, he is murdered and the only suspects are in a confined area, all swearing that they saw nothing. This is the conundrum facing NYPD Detective Michael Lord before he, too, is threatened. Fortunately, he is accompanied by his friend, Dr. Rees Pons, who attempts to aid him by calling on his knowledge and experience as a psychologist.

As one of the most creative writers of impossible Golden Age detective stories, King incongruously begins with an epilogue, concludes with a prologue, and even provides a "Clue Finder" that reveals all the hints that would have helped the astute reader solve the crime that could not possibly have been perpetrated.