Soon after a Chinese princess comes to the US to buy planes for her people, she is murdered by a poison dart fired by an air rifle.

A private detective, who has been shot, stumbles into the office of Michael Shayne (Hugh Beaumont), and dies before Shayne can question him. Shayne finds a baggage ticket in his…

In a series of flashbacks, shows that attorney John Morland has given a lift to a hitchhiker who turns out to be a murderer. As a result, Morland himself is…