The Batman/Bruce Wayne (Lewis Wilson), and his young assistant, Robin the Boy Wonder/Dick Grayson (Douglas Croft), hit on the trail of a Japanese sabotage ring, when Bruce's girl friend, Linda Page (Shirley Patterson), asks him to help her free her uncle, Martin Warren (Gus Glassmire, who has been abducted by the sabotage ring. Dr. Tito Daka (J. Carrol Naish),leader of the gang, plans to steal the city's supply of radium, and forces Warren to locate the vault where it is stored. Daka sends his henchmen, along with a zombie, which he controls by the means of a special microphone, to steal the precious metal, but Batman follows and succeeds in routing the gang in a terrific battle. One of the captured henchmen reveals the radium was to have been taken to The House of the Open Door. Disguised, the dauntless duo, Batman and Robin, visit that hideout and find Linda bound, gagged and unconscious. Linda is rescued. Daka transforms Warren into a zombie, and plots the derailment of a heavily laden supply train, but, once again, he is thwarted by the crime-fighter and his young pal. Trap and counter-trap follow in breath-taking rapidity, as the Batman and the Japanese agent who would steal America's Victory Plans, following the cowardly 1941 attack on Pearl Harbor, wage all-out war on each other.