Dr. Cyclops

Why would a physicist send for four explorers to come to Peru, and what is he doing alone in the jungle with a deposit of radium? Ernest B. Schoedsack follows Dr. Alexander Thorkel (Albert Dekker) and the visitors who answer his summons, among them Bill Stockton (Thomas Coley). When they threaten to end his experiments, Thorkel shrinks them to one-fifth their size and goes on working, sure of himself and deaf to anyone who objects.