Once again the eminent detective is presented with a series of seemingly impenetrable cases: an anonymous but illustrious client employs him to rescue the daughter of a famous personage from the clutches of a roguish aristocrat and suspected murderer; a retired art-supply dealer asks him to investigate the suspicious disappearance of his wife with a neighbour and a stash of money; a veteran of the Boer War appeals to him to track down a missing friend; a man has become convinced that his wife has been sucking their baby son's blood. Will the most famous of sleuths be persuaded to offer his services and set off in pursuit of the criminals?