The first film Sirk directed upon signing his multi-year contract with Universal was this post-WWII-set nautical thriller, starring Macdonald Carey as a U.S. Naval Intelligence officer who goes undercover to rescue a scientist kidnapped by a villainous Nazi commander (and thereby thwart a plot by the remnants of the Third Reich to steal atomic secrets) and sink a German submarine hidden off the coast of Mexico. A taut and suspenseful entertainment, Mystery Submarine finds Sirk playing with genre tropes and again confronting the global threat posed by Nazism, even after Germany’s WWII defeat.