Karloff, on loan to MGM after his smash success with Universal Studio's FRANKENSTEIN, plays the evil doctor with twitching mustache and three-inch fingernails. He and daughter Loy are off to fetch the scimitar and golden mask of Genghis Khan. Once obtaining these artifacts from the tomb of
the great warlord, Karloff will be able to destroy the white man and become conquerer of all the world. Stone, in his pre-Judge Hardy days, is a Scotland Yard detective trying to stop Karloff, but he is too late. Karloff gets the mask and sword and proceeds to carry out his wicked plans. With the
aid of Loy, he conducts a series of bizarre, yet gleefully sadistic, sets of torture...