With a special telescope, Dr. Janos Rukh (Boris Karloff) successfully proves that years ago a meteorite landed in Africa containing an unknown, but extremely powerful element. Dr. Benet(Bela Lugosi) form an expedition led by Rukh to locate the element. Unexpectedly, Rukh discovers "Radium X,", even more powerful than radium and very radioactive and Karloff becomes contaminated and can kill anyone by just touching them. The sparks really fly between Lugosi and Karloff in this classic science-fiction film during the post-World War II era. Director Hillyer used a few standing sets from "FLASH GORDON" series which was being filmed at the same time and also inserted some footage of electrical machines from Frankenstein. Universal kept the public unaware of the special effects being used in this great classic film. Karloff and Lugosi were at their very best and they both enjoyed working together and will be enjoyed by future generations.