A 7-years-later sequel to Gnomeo & Juliet sounds like a joke, I would say. Except it doesn't even. If it were a joke, it would be one with a punchline that nobody could get, because who the hell remembers that Gnomeo & Juliet exists? It's an entry in a spirited game of "who can remember the more obscure, long-forgotten cinematic detritus", not a joke.

All that being said, Sherlock Gnomes now exists. Near as I can tell, it exists for the solitary reason that "Gnomes" and "Holmes" mostly rhyme with each other, and I was all set to do a bit where I pitched out other possible titles for future entries, but the film spoiled it by opening with the exact same joke. Except where mine were things like The Fall of the Gnoman Empire, and other things that actually rhyme with "gnome", screenwriter Ben Zazove is content to go with anything that has a long O sound, like Indiana Gnomes.

Anyway, the action is set sometime indistinctly after the end of the last movie, with the blended concrete garden gnomes of the Blue and Red factions united by the marriage of Gnomeo (James McAvoy) and Juliet (Emily Blunt) in the backyard of a human married couple played, for about 5 seconds, by Julie Walters and Richard Wilson. The whole populace has moved to London, at the worst possible time: a rash of inexplicable garden gnome thefts has been ongoing for some time, and this has aroused the suspicions of the great gnome detective, Sherlock Gnomes (Johnny Depp, who sounds like he was taking this much too seriously), convinced that it's the work of his "dead" archenemy, a small statue of the mascot for Moriarty's Pies (Jamie Demetriou). Suffice it to say that Sherlock is right, and Moriarty's latest target is the garden where Gnomeo and Juliet live, meaning that the lovers (currently in the midst of a low-energy, but ongoing quarrel) must team up with the egomaniacal genius and his longsuffering assistant Watson (Chiwetel Ejiofor) to find out what's afoot.

There's already at least one of the film's many lingering, unanswered questions in that paragraph - why a pie mascot? - but it's not sporting to approach a film with such a giant, colorful "KICK ME" sign pre-attached with the intention of finding every last little fault. So let me instead list everything I can come up with that's praiseworthy. First, much like Gnomeo & Juliet, Sherlock Gnomes is pretty impressively rendered: the characters are chunks of painted concrete, and the film is eager to remind you of that at every opportunity. It even goes so far as to subtly alter the textures of some characters to look "newer" than others, notably the slightly shiny Sherlock and Watson, who presumably spend their winters in an office pondering crimes, rather than in a garden under a foot of snow. Plus, this film possesses a substantial cast of non-gnome characters, including those cheap plastic waving Chinese cats, a Barbie-style doll voiced by Mary J. Blige and ever so loosely based on Irene Adler from the Holmes stories, a pair of gargoyles, and a tin rooster, and every one of these is designed to look distinctly different from every other.

Second, it's a nice change of pace to see a Holmes adaptation, if we can call it that, that plays the super-detective as an abrasive dick, and Watson as a smart, talented thinker in his own right (it's also interesting that Watson has been vocally cast colorblind: the gnome is himself white, but Ejiofor works quite well in the role). Third... I guess that's everything. There's something at least interesting-ish in the film's message, which purports to teach our 8-year-olds that the key to a longstanding romantic relationship is mutual respect and good listening skills, and that's as true for Gnomeo and Juliet as for Holmes and Watson (I've never seen a version of these characters that so openly encourages a reading of them as a couple; oddly, this does not seem to be a reading that the filmmakers were even a little bit aware might be made). I'm not sure why on Earth that message is residing in a dopey little adventure-comedy for children, but there you have it.

The rest of the film isn't "bad", so much as it is flagrantly mediocre. It did not have to be thus. The plot's meandering tour of London locations from a gnome's-eye view yields some fun, lively locations, and there's enough absurdity baked into the material that it could easily have been a pretty enjoyable loopy comedy. But that's not at all the approach the filmmakers - including director John Stevenson, the lesser-known half of the Kung Fu Panda directorial team - have taken. Indeed, the film is peculiarly allergic to comedy in any other form than a mild, glancing whimsy. Pretty much everything about Sherlock Gnomes is mild, for that matter: the whole thing feels very much like Gnomeo & Juliet but turned down in intensity. And it's not like that was a very intense movie in the first place. But where that film had a slightly manic, yelling quality to its humor, Sherlock Gnomes is content to make silly observations; where that film put its peculiar score, adapted from the songs of executive producer Elton John, front-and center, Sherlock Gnomes simply pipes them in with the approximate energy level of the music playing inside a doctor's waiting room.

Basically, I think the difference between this films can be summed up thus: Gnomeo & Juliet is a generic, crappy kids' film with inexplicable delusions of being a madcap adventure for adults even more than their children. Sherlock Gnomes is a generic, crappy kids' film that's content to be a generic, crappy kids' film. It's not the worst incarnation of the form one can imagine - The Emoji Movie is still visible in the rear-view mirror, and as long as I have that film's taste in my mouth, Sherlock Gnomes feels like a minor classic - but if you happen to have children who are eager to see the film, for sad reasons of their own, just remember that you can always pretend to have lost your car keys.