At the time of publication, this book received mixed reviews. Some critics cited it as being brilliant and among her best, whereas others claimed that it is lacking in plot, and too full of psychology. This last complaint is perhaps the reason why I ranked it among my top favorites, (excluding her Westmacott novels).
The story takes place in Petra, Jerusalem, which to me is neither here nor there, as the setting itself doesn't really play any essential role in the story. The first half of this book, Part I, focuses primarily on the Boynton family. It is essentially a psychological glimpse, or character sketch, of a family who is governed by a sadistic matriarch. The other members of the Boynton family, including three step-children, one daughter-in-law and one daughter, all ranging between ages 17-30, are entirely dependent on Mrs. Boynton, both financially and psychologically. They are all stuck at home under their mother's thumb; she limits their contact with the outside world and controls their every move as though she has them hypnotized. Christie's description of Mrs. Boynton as a domineering tyrant is haunting, and the torment that her children are put through is worthy of anyone's pity.
I enjoyed the first half of this book because of it's focus on the family and their influence on the people who are outside looking in, the unknown observers. The second half, however, was exactly what I would expect any of Christie's crime novels to be; it was both predictable and unexpected at the same time. Part II ran like a typical Hercule Poirot novel. The pattern, the tone, and the plot are characteristic of a Christie story. Poirot as a character is his usual egotistical, over-confident self. He pulls his clues and his solution seemingly out of nowhere, and sets up his dramatic reveal at the end as he always does. He gathers everyone in a room and goes through his process step-by-step until he finally reveals the murderer, who really has nothing to do with the speech and clues that he has just spent a hundred hours spewing out.
After reading as many of her novels as I have, (over 40), some solutions are starting to become a little too obvious. I had a sneaking suspicion as to who the murderer would be revealed to be, but I doubted it because it seemed a little too obvious, as it was the character least likely to be the murderer. But as most of Christie's novels turn out, it often IS the least likely character.
I would recommend reading this novel only if you are bored with her regular crime stories, and enjoy the ones that delve into the psychology of the characters.