
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 Nazi smuggling ring, but the location of the missing diamonds continues to elude him.

as Michael Shayne

as Merle Garland

as Juan Arturo O'Hara

as Helen Shaw

as Vanderhoefen

as Rudolf Hagerman

as Friedrich Gerber, alias Nappy Dubois

as Ethel

as Charlie

as Mrs. Bertha Toby

as Mr. Toby

as Alexis Fournier

as Judge

as Capt. Brown

as First Officer Richards

as Inspector Peterson

as Joseph P. McCordy

as Miss Hoffman

as Theodore H. Sherman Jr.- Printer

as Clerk (uncredited)

as Man at Ship Dock (uncredited)

as Ship's Passenger (uncredited)

as Helper (uncredited)

as Mrs. Flaherty - Mike's Landlady (uncredited)

as Honolulu Cop (uncredited)

as First Junior Officer Brooks (uncredited)

as Man at Ship Dock (uncredited)

as Jonesy

as Ship's Purser

as Porter

as Maid

as Taxi Driver

as Salesgirl

as Taxi Driver

as Ship's Doctor

as Felix

as Ship's Pageboy

as Police Sergeant

as Thomas

as Court Clerk

as Kali - Chauffeur

as Barney - Cop

as Sailor Carson

as Ship's Doctor

as Truck Driver

as Ship's Ticket Agent

as Otto

as Minor Role