Four strangers arrive at the solicitors' office of Puckle, Puckle, and Nunnery. They have never met and have no idea why they have been invited. But they - along with a missing man - are descendants of the late Algernon George Culver Mayton, the inventor of 'Mayton's Marvellous Mixture' and each entitled to a portion of the Mayton Fortune. But before they can split the money, the missing man must be found. They begin their search, but then Detective Sloan receives a call that one of the legatees had died following an attack of food poisoning. Now detectives Sloan and Crosby must determine whether the deceased merely ingested a noxious substance by accident, or if the legatees are being picked off one by one. And when matters of money and family rivalry are involved, there is almost certainly foul play afoot.