In Victorian England, a divisive election is fast approaching. Passions are so enflamed that Thomas Pitt, shrewd mainstay of the London police, has been ordered not to solve a crime but to prevent a national disaster. The aristocratic Tory candidate--and Pitt's archenemy--is Charles Voisey. The Liberal candidate is Aubrey Serracold, whose wife's dalliance with spiritualism threatens his chances. Indeed, she is one of the participants in a late-night séance that becomes the swan song of a stylish clairvoyant who is found brutally murdered the next morning in her house on Southampton Row. Meanwhile, Pitt's wife, Charlotte, and their children are enjoying a country vacation--unaware that they, too, are deeply endangered by the same fanatical forces hovering over the steadfast Pitt.