Phyllis Clavering (Louise Campbell), the girlfriend of Captain Drummond (John Howard (American actor)), is kidnapped. Murderer Mikhail Valdin (J. Carroll Naish) and his sister, Erena Soldanis (Helen Freeman Corle), seek revenge for the death of her husband, sent to the gallows a year ago through Drummond's actions. Though Valdin could shoot Drummond, he informs the captain that it would be too quick. Drummond and his friend Colonel Nielsen (John Barrymore) are instead given a series of riddles to solve.