When he is jilted, Alan Remington, the son of a wealthy Washington politician, falls into a state of deep depression. On the advice of Professor Hollister, from whom he is purchasing a death ray, the elder Remington attempts to divert Alan by providing him with excitement. At this time, a gang of foreign agents, led by Darwin Kershaw, Remington's secretary, kidnap both the inventor and his daughter, Carolyn, and steal the death ray, but not before the resourceful girl has thrown the control key to the ray out of the window, where it lands in Alan's car. The conspirators attempt to regain the key, but they are mockingly foiled on several occasions by Alan, who thinks they are men hired by his father to jolt him out of his depression. Alan eventually realizes that the men are seriously trying to kill him, and he sets out to bring them to justice. Alan prevents the agents from destroying several naval gunboats, rescues the Hollisters, and rounds up the aliens, handing them over to the F. B. I.