Adventures of Smilin' Jack: 15 Fathoms Below on AllMovie

Shot down by a Japanese submarine in chapter six of the Universal serial Adventures of Smilin' Jack, the clipper carrying Jack (Tom Brown), Janet (Marjorie Lord), Mah Ling (Cyril Delevanti), and Fraulein Von Teufel (Rose Hobart) and her Axis spies plunges into the sea. The Japanese submarine crew enters the still floating aircraft, demanding that Mah Ling reveal the location of the secret passage from China to India or else. Jack and his friend manage to overpower the enemy and take over the submarine. In order to remain anonymous, Fraulein Von Teufel, still in the guise of foreign correspondent Gertrude Muller, kills one of her female operatives (Grace Cunard) with a posioned dart, letting Jack believe that the dead woman was Von Teufel. Having learned from the Japanese sub commander (Edward Colebrook) of the impeding attack on Pearl Harbor, Jack signals what he believes to be an American freighter. The freighter captain (Edward Peil Sr.) is really in the employ of the Japanese and orders full speed ahead towards the defenseless submarine.