Dr. Calgary is confused by the dismay with which the Argyles receive this good news. Why aren't they happy that their brother was not a murderer? It soon dawns upon him that Jack as the murderer was the easy solution - the delinquent, the misfit, excuses could be made for his conduct. But with this happy illusion gone, the Argyle family is confronted with the fact that one of their own committed the crime. They have been living among a murderer and never known it. Now the innocent must suffer under the shadow of guilt. Whether the murderer will ever be found after so much time is doubtful. The innocent will never be cleared and will be suspected along with the truly guilty person.
Dr. Arthur Calgary feels responsible. He has destroyed the peace in their lives and shattered the security of the innocent. Now he feels that he must uncover the true identity of the murderer and free the other inmates of Sunny Point. And along the way, you'll discover who he solves the crime for! He is 'The Young Man in Love With One of the Woman Suspects' although he is more middle aged...
So I know the cover is horrible, but don't don't judge the book by its cover. This novel is one of the best. It deals with the concept of innocence - protecting those not guilty over everything else.
Christie's mystery novels featuring no specific detective, no youthful pair in them are the most different, most intriguing and most psychological. They have a dark and dreary atmosphere to them. The books are a bit odd, more personal and more intricate than the others. Imagine walking from a sunshiny, normal world, into an eerie, shadowy one where things live in the dark. You don't know what might happen, what type of people you may run into, and what the mystery is. It's just queer and so fascinating to read.
I loved the psychological representation of Rachel Argyle, the mother, in this novel. Christie usually portrays crime as hereditary (which I disagree with) but in this novel she has also shown the psychological gap as a result of blood; how the adoptive mother, Rachel has difficulty in connecting with her adopted children. She can't get past the barrier of blood. Although this isn't strictly true, it was so in Rachel's case because she herself was blind to anything but her own psychology. I've seen adoptive mothers find peace with adopted children and even understanding despite the blood barrier, but Rachel was unable to understand her children although she never knew it.