It seems to me that to make good, effective children's horror must have one of the highest degrees of difficulty out there. You have to thread the tiniest of needles to find something that's sufficiently terrifying and otherworldly on the one hand that it's actually scary, the kind that worms its way into your bones; on the other hand, you have to make sure that it's safe and domesticated enough, with little enough blood and trauma, that it won't cause any lasting harm or more than one sleepless night.* In my own youthful experience as a pre-teen horror fan, one of the few artists who reliably got this mix just exactly right was John Bellairs, who produced 15 horror novels for children between 1973 and 1992 (the last of these published posthumously), most of them falling into a hugely formulaic but satisfying mixture of decaying buildings in murky places and shadowy human forms perpetrating simply dreadful, ghastly sins.

27 years after the author's death, the first feature film based on his work has finally been released after many years bobbing around in development. The House with a Clock in Its Walls has plenty of the ingredients one might want to assemble to make a good kid-friendly horror picture, too: besides basing itself in Bellairs's first and most laureled children's book, it comes with the imprimatur of Stephen Spielberg's Amblin Entertainment, whose 1984 Gremlins is one of the high-water marks for family-friendly scary movies, and it snatched up a director whose commitment to giving the audience horror without pulling any punches is, at least, undeniable. That it snatched up Eli Roth out of all the people to whom that description applies is perhaps disappointing, but one must learn to live with these things.

Whether all of that is enough to make The House with a Clock in Its Walls a new classic of children's horror cinema is one that the children will have to answer. For myself, I have to confess a moments' whisper of disappointment that the almost tangible smell of dusty shadows and autumnal damp saturating the 1973 source material have been downplayed in favor of dazzling spectacle: this is a film with at least one eye on the Harry Potter movie audience, and accordingly it favors whimsy over curdled blood. This isn't really a bad choice at all, as it turns out. While Roth has thankfully completely buried his artistic personality beneath the requirements of the Amblin house style, there's still a foggy, fall-ish chill that invades the sparkling lights and overly polished CGI of standard family filmmaking, giving them just a little bit of a hush, a glint of sharpened edge. It's not exactly "scary", except in maybe one sequence set in a room full of leering old-fashioned mechanical dolls, but it has damp, and gloom, and a foggy ol' cemetery, and those count for a lot of enjoyable atmosphere.

The pleasingly unrushed story centers on recently-orphaned 10-year-old Lewis Barnavelt (Owen Vaccaro), who in 1955 relocates to the snoozy town of New Zebedee, Michigan, to live with his previously unheard-of uncle Jonathan (Jack Black). In no time at all, Lewis discovers that Jonathan and his dear friend and neighbor Florence Zimmerman (Cate Blanchett) are both magic users; in Jonathan's case, not much more than some amusing visual trickery, but it's enough for Lewis to find a brand new world to explore and learn about when the everyday world proves a bit too unforgiving for an out-of-shape kid who likes reads way above his level and insists on wearing goggles to emulate his favorite matinee hero. Boilerplate stuff (Bellairs made, literally, an entire career out of socially awkward boys who like books more than sports and cry easily), and not really helped out by the ways in which Eric Kripke's screenplay handles Lewis as more of a sad person unto whom things happen than an active force, nor by Roth's general disinterest in directing his child actors (there's not a single notably good performance from the entire juvenile cast, of whom two besides Vaccaro have featured roles). But part of the appeal of boilerplate scenarios is that, even if it takes more than a film like this has to make them really and truly splendid, it also takes more than  film like this has to severely fuck them up.

There's some big, over-the-top stuff about the dead warlock who used to live in Jonathan's house, Isaac Izard (Kyle MacLachlan in the short bursts in which we see him, generally slathered in latex and voice distortion), who left a magic clock within its walls for unknown but surely ill reasons; but really, the bits of the movie where it goes most in on this are its least engaging (not least because, in its biggest change from the source material, the movie finds a way to put the clock at the center of a huge, and generic, action setpiece). Its strengths are rather scattered across a number of worthy places: Jon Hutman's absolutely delicious production design, making the house a full-on mansion of giant rooms full of curlicues on the walls and elaborate props; Kripke's clean, efficient script, not belaboring any of this or trying to go bigger than the material wants or needs; the keen evocation of the inscrutable personal rules of late elementary school.

Best of all, it has Black and Blanchett, who are having an enormously good time as the silly-serious adults in this elaborate fantasy world. Black's been here: The House with a Clock in Its Walls bears many similarities to the 2015 "autumnal horror-fantasy for children" Goosebumps, which he also starred in, with the major exception that House isn't insipid drudgery. Playing a tart-tongued purple-clad suburban witch is, near as I can tell, untrod ground for Blanchett (the film does add a tragic backstory for Mrs. Zimmerman, probably not only or even primarily for Blanchett, but it does at least give her some stuff to do that's all silent and in the back of her eyes), but it's no surprise that she nails it, finding exactly the right amount of "okay boys and girls, let's have fun" energy to shade into kitsch or camp without actually falling into either one of them, and thereby undercutting the movie (indeed, her work here is much better than the last time she played a mostly comic character in a light, playful movie, this summer's Ocean's Eight).

The two grown-ups add precisely the right energy - here upbeat, here serious - to keep the film moving in the right direction even when the actual protagonist is a bit of a blank spot; they also tend to ground the film more in fantasy than in horror. And maybe that's a good thing, maybe it's not. It does make the film a bit of a lark more than anything else. A spooky lark, with a really good haunted house, but this definitely falls more on the side of "it's fun to be scared" than "it's terrifying & cathartic to be scared". Which is fine, of course: there are few enough decent children's fantasies anyway that this is enough to stand out whatever its generic allegiances. We'll never know for sure, but I'm pretty sure if this movie came out when I was 9 years old, I'd have worn out the VHS tape re-watching it.

*This isn't, of course, mostly for the sake of the children; children, I think, are not merely able but eager to watch all manner of decapitation and gutmunching and vivisection, the gorier the better, and tell each other the most elaborately horrific tales, and be none the worse for the wear. Or perhaps I and my childhood friends were merely beastly little psychopaths, but I have no real reason to assume that was the case, even if I did grow up to become an academic.