This suspense comedy, whose central characters are Inspector John Horn and his sidekick, soon-to-be-wife, Francesca Flaminare, involves the attempt by a secret society of Assassins in India to steal near-bomb-grade Plutonium in order first, to construct a bomb and then, using the threat of thermonuclear war if they are not recognized, to declare a separate state. One of their own submits to being killed in order to confuse the police by an apparent "perfect crime." Several of their number are murdered to silence them as the police close in. Finally, the ring-leader, a doctor, is apprehended and handed over to an Indian Army officer to stand trial in India, where he will be executed. After they have solved this case, Horn and Francesca marry one another.