This is possibly MARGARET RUTHERFORD's most satisfactory excursion into Agtha Christie-land and she's helped by a delightful Ron Goodwin score that emphasizes her character with an infectious main theme and the gorgeous B&W photography, full of sinister shadows and proper atmospheric effects.
Furthermore, Miss Rutherford is surrounded by some formidable British talent, such as Stringer Davis (his Mr. Stringer is always a delight), Robert Morley (blustery but fun), and most notably, FLORA ROBSON, remarkable as the timid companion of an elderly woman.
I've seen most of these Miss Marple mysteries from the 1960s, and this has got to be one of the best. It moves at a swift gallop (unlike some of the more tedious, slow-paced BBC versions), and the accent is on the humorous characterization that Rutherford is capable of. Purists may not think it serves Agatha Christie well, but taken on its own as a piece of comedy/mystery entertainment, it stands up well in that genre.
Highly recommended.