An odd elderly man is found dead at an obscure country hotel. It would be most convenient if his overdose of sleeping medication were just an accident or even suicide. But is it that simple? Or is there a cold-blooded murderer at work? His family stands to lose a tidy sum in insurance money if the verdict is suicide—and the family can definitely use the money. Contrary to most mysteries where no one wants a murder to have happened, the heirs begin drumming up evidence to try to prove foul play. The amateur "sleuths" do find some interesting clues, but while they're beavering away, Inspector Mallett of Scotland Yard is following his own line of investigation.