At a quiet country hotel, an elderly man with unusual habits—including keeping a scrapbook of morbid quotations—is found dead from an overdose of sleeping medication. While such deaths are often ruled accident or suicide, this case takes an unexpected turn: the deceased's family actively seeks to prove murder. Their motivation? A substantial insurance payout that would be void if the death is ruled a suicide.

As the heirs hunt for evidence of foul play, Inspector Mallett of Scotland Yard pursues his own investigation, following a separate trail that may lead to a very different conclusion. In this distinctive mystery, the question isn't whether anyone wants to prove murder—but whether murder actually occurred.