A British scientist has created a death ray which can destroy an entire army in seconds. A villain murders him, steals his invention, and plans to sell it. Drummond discovers the killing and takes the case, but soon finds himself in trouble with Scotland Yard, and accused of murder. Now he must clear his name as well as stop the crooks. Stars: John Howard, George Zucco, Heather Angel, H. B. Warner, Reginald Denny, and E. E. Clive.