Dr. Fenniman has a surprised communication from a cousin he doesn't know, who lives in Prague, and she indicates that she and her family are having serious problems and needs help from him. Off he goes to Prague to help her in whatever way he can, and decides to get his relatives to the U.S. But it is not simple, and Fenniman pulls in his lover, his secretary, and the street urchin turned teenaged helper, bringing them all to the beautiful old city, where they become tangled with a psychopath who is planning to overthrow the government and declare himself ruler of the country, an agenda that involves a talented maker of puppets, the rescue of a young child, and murder.