Did we really need a secondhand retelling of Robert Louis Stevenson's classic tale as seen through the eyes of the eponymous, non-canonical housemaid? This is such a well-known story that adding a fresh perspective may have seemed like a good idea at the time; on the other hand, what possible insight could Mary (Julia Roberts) offer when she’s either blind as a bat or dumb as a rock?
She’s not alone, though; everyone in this movie who isn’t Dr. Jekyll/Mr. Hyde suffers from Lois Lane Syndrome. The closest anyone ever comes to pointing out the uncanny resemblance between the "master" and his "assistant" is remarking that "they do look a bit alike." More like a yottabit.
John Malkovich could have been as good an Edward Hyde as we was a Vicomte Valmont, and that’s precisely what made him wrong for the Henry Jekyll part. Casting him in both roles not only completely misses the original novel’s Apollonian/Dionysian dichotomy theme, but also makes the rest of the characters, especially the heroine, like complete morons. And since everyone in the audience knows, if they know nothing else, that Jekyll and Hyde are one and the same, what the hell was the point anyway?