There are certain casting choices that are so ineffably perfect that it's impossible for the reality to match up to the fantasy one concocts upon learning of them. "Ian McKellen as a geriatric Sherlock Holmes in 1947" is, for me, one such bit of casting, and sure enough, Mr. Holmes (for that is the movie in which that marriage of actor and character takes place) turns out to be far less exciting in practice than in theory. This is at least in part because it's not really the "old Holmes solves one last case, despite being a long-retired country gentleman" scenario that one might hope for, but the bigger part is what replaced it: "an old man fighting hard against the loss of his memory painfully, and with only some success, reconstructs a series of not particularly interesting events that transpired decades earlier, while being somewhat annoying to the people responsible for taking care of his 93-year-old ass".

This is, if nothing else, not a tremendously difficult challenge for McKellen to meet. Sure enough, his portrayal of a cantankerous, doddering old man is flawlessly done, but also somewhat generic. This is for McKellen exactly the same kind of exercise that The Last Station was for Helen Mirren or Philomena was for Judi Dench: a slightly complicated but basically standard-issue role that doesn't require much from the British acting legend who needs to do little more than recite lines in a sufficiently prickly tone to win loving applause from the kind of audience that can be relied upon to watch these movies.

It's even less of a challenge for Laura Linney, heartbreakingly underused and damnably ineffective as the put-upon housekeeper, Mrs. Munro, irritated by Holmes's behavior while her young son Roger (Milo Parker) falls under the old man's spell. Stuck with no arc and a terrible accent, Linney is an active detriment to the film, throwing cold water on the pleasant momentum it's sometimes able to build up. It doesn't help that her character has a tendency to force the movie into its most uninteresting directions; it's the very definition of a thankless role, and Linney sinks to its level.

Still, Mr. Holmes ends up being at least a little bit charming. Bill Condon's direction (in what is, for all intents and purposes, a remake of his McKellen-starring Gods and Monsters) is lighthearted in ways that Jeffrey Hatcher's solemn adaptation of Mitch Cullin's novel isn't, particularly in the flashback segments set in the '20s - not that the film makes particularly good use of either of its time periods. Watching McKellen play-act dementia could quickly turn into a dreary exercise, but Condon is exactly the director to keep the actor focused on creating a truthful character without it becoming a grim agony. It's the perfect movie to watch on cable with your dad with only minor regret; worse fates have befallen Sherlock Holmes, though I'd much rather watch the campy '40s-style Holmes picture that puts in a cameo appearance.