Detective Michael Shayne boards a Hawaii-bound ocean liner on the trail of stolen industrial diamonds and a German smuggling ring.

In order to win back his girlfriend, Mike Shayne promises to give up his detective practice and get a job as riveter in an aircraft plant. He quickly finds himself investigating the theft of industrial diamonds from the plant's safe and, utilizing a variety of false identities, traces them first to a dress factory and later to a Hawaii-bound ocean liner. Escaping several attempts on his life, he is able to uncover a German smuggling ring, but the location of the missing diamonds continues to elude him.—duke1029

Private Detective Michael, in pre-war America, in compliance with the wishes of his girlfriend, Merle Garland, takes a job at an airplane factory, and immediately the diamonds used for special instruments are stolen in what Shayn suspects is an inside job. The trail leads him to a dress manufacturer who is a German agent, smuggling diamonds to Hawaii as dress buttons. On the boat to Hawaii, Shayne finds that an old friend, Helen Shaw, is working with the smugglers. After he and a federal agent, Juan Arturo O'Hara, quit chasing each other and, alter trapped by the gang, the case is solved and the smugglers brought to justice.—Les Adams <[email protected]>