Jack Cardiff was the director of photography, Anthony Powell, the costume designer, Nino Rota composed the score, Anthony Shaffer signed the screenplay and the list goes on and on and I haven't even mention the cast yet. Agatha Christie's novels have a structure that is a sort of cardinal rule. Murders, a set of suspects, all of them with a motive for the killing and then the unmasking of the killer or killers. Anthony Shaffer, the author of "Sleuth" milks it for all its worth. Snippets of wit trying not to obstruct the implausible plot. Tough gig. Dressed in a fantastic Nino Rota score, Jack Cardiff does his marvelous thing and Anthony Powell envelopes the stars in costumes that are not only stunning but character revealing in the most entertaining way. Peter Ustinov's Poirot is great fun and the cast moves through the carefully plotted story with disarming precision. Mia Farrow is the only one who plays it for real. Her jealousy is so believable that in a way we're guided by her pain and dismiss the obvious. Bette Davis does a Bette Davis impersonation for our benefit, I guess, and she gets away with it. Maggie Smith, Davis's long suffering lady in waiting, is always fun to watch and I imagine she had a lot of fun herself pushing around Bette Davis. My favorite was Angela Lansbury's Salome Ottobourne. Her alcoholic pulp fiction writer is a complex, compassionate, realistic caricature. David Niven,Jack Warden, Jon Finch, Olivia Houssey, Lois Chiles, Jane Birkin etc complete the who's who of this whodunit. I haven't mention the director: John Guillermin, from "The Towering Inferno" fame.