Solidly executed, twisty whodunnit with a brisk undercurrent of homosexual persecution, as is appropriate for the only screenplay collaboration from Anthony Perkins (!) and Stephen Sondheim (double !!). James Mason is as usual superb; he’s perhaps the most reliable utility player in cinema history, consistently lending star quality to character parts without undermining them. Dianne Cannon is also terrific. James Coburn is not.