Mrs. Boynton is determined to have everyone around her in subjection including all the members of her family. She is described as a 'mental sadist.' She takes her family to Petra, where she dies. At first, the death appears to be a natural one. However, a missing syringe raises questions and soon Hercule Poirot is asked to look into the matter. Was the murder committed by one of the brow-beaten family members? If so, which one? Or maybe all the family plotted together to kill the tyrant.I loved this book because of the psychological aspects. How does a old woman brow-beat grown-up children? Can murder be justified to save others from a mental breakdown? I also developed an attachment to the family and was rooting for them. I also enjoyed the development of the story and the opportunity to bond with the characters before Poirot enters the scene. He is only in the second half of the book and brought in only to solve the mysterious death.