This Agatha Christie story has a gripping, instant hook but a rather underwhelming resolution; by the time you finally learn who Evans is and why they didn't ask him, you may wish that you never wondered in the first place. Hugh Laurie aka Dr. House, who writes, directs and plays a supporting role, does not bring very much new to the table, apart from a flourish here and a photographic trick there, and Will Poulter is merely OK as Bobby Jones. But Lucy Boynton is magnetic as Frankie: beautiful, playful, witty (especially in the first of the three episodes), she really brings the character to life. On the basis of this performance, she totally deserves a regular spot in a possible future Agatha Christie series - one that, hopefully, will resolve its cases in fewer than 175 minutes. *** out of 4.