Possibly the most enjoyable of the delightful Miss Marple series of mysteries, Murder Most Foul benefits from its setting inside a third-rate theatrical troupe. This allows series screenwriters David Pursall and Jack Seddon to create (courtesy of Agatha Christie, of course) a cast populated by some rather extreme types, as well as letting them set their heroine loose in a setting that is somewhat alien to her. Margaret Rutherford, of course, doesn't allow anything alien to deter her Marple, and she seems to enjoy discovering how Marple would react to these various types -- mainly by taking them in her very proper British stride. The plotting is appropriately intricate, although director George Pollock does his customarily reliable job of keeping all his ducks in a row so that the viewer never worries about getting lost. While there are the usual minor logical lapses that are common to the genre -- no matter how hard they try to justify it, there simply is no excuse (other than it makes for more suspense) for Marple not to explain matters more thoroughly to the doubting Inspector -- they won't bother most viewers, who will be too absorbed in the mystery, and too entertained by Rutherford and company. Ron Moody is thoroughly enjoyable as the vain would-be-Belasco of the troupe, Alison Seebohm makes her semi-mystical flake believable, and the rest of the cast is quite fine.