As a person who has seen barely a flicker of Downton Abbey on television, I can’t predict whether the movie spin-off–directed by Michael Engler and written by the show’s creator, Julian Fellowes–will be everything longtime fans have hoped for. But as a one-off, it’s a featherweight delight, like the prettiest pink-and-white cake on the tea tray. It’s 1927, and the denizens of Downton are in a tizzy: King George and Queen Mary are planning a trip through Yorkshire, and they’ll be stopping off for one night at the estate.