I forgot to mention last night in recapping my viewing that I did watch the POIROT mystery MRS. McGINTY'S DEAD. I had read the book years ago and didn't remember it, but, of course, having seen Margaret Rutherford's MURDER MOST FOUL (which was based on just enough of the book to give away the deception Christie uses to mask her killer), I had no trouble figuring out the murderer well before the revelation.
Still, it's wonderfully done, and featured two superb character actresses: Sian Phillips and Zoe Wannamaker.