In the waning days of WWI, a U.S. "Mystery Ship," sets sail for the coast of Spain towing a submarine. Their mission is to find and sink a U-boat that has been especially effective in attacking Allied shipping. Posing as a harmless schooner, the mystery ship is in fact fitted with a formidable gun capable of sinking a U-boat. Stopping in the Canary Islands to refuel, the crew interacts with locals involved with Germans, and with Germans themselves, including the sister of the U-Boat commander, who is lurking offshore waiting for the coming battle.

"Thrill after thrill will hold you breathless in Fox Movietone Drama"

Credits

John FordDirector

George O'BrienCmdr. Robert 'Bob' Kingsley

Marion LessingAnna Marie Von Steuben

Mona MarisFraulein Lolita

Walter C. KellyChief Mike 'Guns' Costello