Believing the deception, Diana marries Ronald. Rukh now begins to use his radiation poisoning to kill off the expedition members. He marks each death by disintegrating a single statue on the exterior of a church across from where he is hiding. Each time, he focuses the radiation through a window using a raygun-like device. He manages to kill both Stevenses before the police realize what is happening. Dr. Benet helps them set a trap by convening a scientific conference at his home to discuss Radium X, but Rukh secretly gains access and kills Benet. He has saved his revenge on Ronald and Diana for last but finds himself unable to kill his former wife. This hesitation brings him to a confrontation with his mother, the most important woman in his life. She has foreseen her son's growing madness and smashes the last of his antidote bottles in order to stop him. As the Radium X begins to consume him from within, Rukh jumps from a window. He disappears in an explosive flame, having been vaporized before reaching the ground.