Better than a bad Christie, but struggles to maintain its inertia over its length. Poirot novels - and some of the most beloved Poirot stories - are short, or, alternately, if they aren't, Poirot enters when it's a tangled mess, and isn't present from the beginning.  The new point of view character is engaging enough (and emphasizes some of the blind spots of the characters in the historical world of Christie), but you never quite feel the murderer is breathing down our neck, or that we race with them to the finish.