Mary Westmacott, the now well-known pseudonym of Agatha Christie, delves into relationships, particularly those of an older sister/younger sister.
At first Laura hates her younger sister. She prays for her to die, attempts to entice the family cat to smother her, and in general, hates this new person who will get the love she wants. But a tragic accident changes everything and younger sister Shirley becomes the total focus of Laura's life. Laura's every thought and action centers on Shirley and making sure she is happy and protected.
The story covers many years and sees Shirley making a terrible choice for a husband and living to reap the fall-out from such a choice. Can Laura step in again to save Shirley? And at what price to herself?
I thought this was an interesting story until the last section and the introduction of Llewellyn Knox. The heretofore interesting tale then downgraded into long winded discussions of philosophy and religion that seemed out-of-place. Be prepared for a rather fantastical ending, but as always with Christie, a highly readable tale.