The Invisible Ray

In this horror movie icon vehicle, Dr. Rukh (Boris Karloff) creates a wonder healing ray (which is conspicuously visible) from the newly discovered element radium X. This ray also has the effect of causing Karloff to glow, gives him the touch of death, and drives him quite mad. The insane doctor is convinced his associate Dr. Benet (Bela Lugosi) has stolen his work and begins a plan to destroy the members of the expedition that discovered radium X.