The Invisible Ray In this wicked horror thriller, Dr. Janos Rukh (Boris Karloff) returns from Africa with a deadly discovery. Exposed to an unknown element, he accidently kills everyone he touches. His friend and colleague, Dr. Benet (Lugosi), develops an antidote that helps but with terrible side effects. As paranoia sets in, the doctor tries to guard his scientific discovery while fighting his uncontrollable urge to kill again. No one is safe from the effects of The Invisible Ray.