It is clear from the very first page of this book that Lois Latter is a character ripe for murder. A medium has warned her to be careful of poison - whether used by her or against her and while she is frightened for a short time she quickly resumes her normal pattern of behaviour - i.e. trying to manipulate everyone around her into giving her what she wants. Jimmy Latter, her husband, approaches Miss Silver when Lois has sudden attacks of sickness and Miss Silver suggests some sensible precautions for them to take.
The household at Latter End is shown to the reader through following Julia - one of Jimmy's step sisters, who does not like Lois at all partly because of her own interest in Antony Latter - Jimmy's cousin. It is soon clear to the reader that the household is like a bomb waiting to go off. Relationships are fraught and subject to many undercurrents. Miss Silver is called in by Jimmy when Lois is found dead of an overdose of morphia. The case is in the capable hands of Frank Abbot and Chief Inspector Lamb. Frank is a long time admirer of Miss Silver though Lamb has some reservations about her.
The way the many strands of the plot are woven together is, as ever, masterly. Means motives and opportunities must be identified and the murderer unmasked. Is it suicide or is it murder? The complex strands of the relationships between the members of the household will keep the reader guessing until close to the end of the story. This is one of Patricia Wentworth's best books in my opinion.