1931年敬请关注！
简介：InthewaningdaysofWWI,aU.S."MysteryShip,"setssailforthecoastofSpaintowingasubmarine.TheirmissionistofindandsinkaU-boatthathasbeenespeciallyeffectiveinattackingAlliedshipping.Posingasaharmlessschooner,themysteryshipisinfactfittedwithaformidableguncapableofsinkingaU-boat.StoppingintheCanaryIslandstorefuel,thecrewinteractswithlocalsinvolvedwithGermans,andwithGermansthemselves,includingthesisteroftheU-Boatcommander,whoislurkingoffshorewaitingforthecomingbattle.…