October 23, 1938

Lamont and Margo are taking a Caribbean cruise together when Captain Nielsen, the captain of their ship, sees another ship on the horizon that is on fire. The cruise ship comes to the rescue and takes on board one "Capitan" Joe and fifteen of his men.

It's a bad idea. Captain Joe and his men are pirates who promptly murder Captain Nielsen and seize his ship. They sail back to a small island that is the lair for Captain Joe and his men, with Lamont and Margo as their prisoners. Lamont becomes invisible as The Shadow, while Captain Joe takes custody of Margo. Lamont and Margo soon find out that something completely different from piracy is taking place on the small island.