Adam Low is a somewhat mysterious spy, high up in the hierarchy. The house is full of James Bond gadgetry, with signal lights, sliding panels and hidden screens. As the action starts, news arrives of a miscarriage of justice, through which a perverted killer has been acquitted because of a lack of evidence. Alec, a professor of anthropology, holds that when the law fails enlightened citizens must step in. Throughout, one is never quite certain what game, if any, Adam Low is playing. A session involving a lantern slides increases the tension. The outcome does not seem to worry the Professor, who goes off quietly to prison, with plenty of books.