Dr. Fu Manchu is on the run but still up to his nefarious schemes. He captures Dr. Petrieâs daughter Fleurette and takes her to London where Alan Sterling, her fiancĂ©, and Nayland Smith track him down. Fu Manchu is cut off from his Si-Fan resources so he comes up with a quick money making plot; turning lead into gold. Burmese stranglers, British seamen, abandoned mansions, a roaring furnace, explosives, and an underground lair all play a part.