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
