I cannot say Ordeal by Innocence is my favourite Christie's novel. But I was looking forward for this TV drama. Part I seemed very poor to me, I couldn't imagine this Dr. Calgery arriving and solving the mystery of the Argyle family. Part II explained more about the story and part III was really powerful. Unexpected ending, Nemesis of the murderer... yes, I can accept this adaption indeed.
Review of Ordeal by Innocence
