The fictional town of Castle Rock, Maine, may be one of the most bedeviled in all of American letters, absorbing trauma after trauma before resiliently cropping up for more punishment the next time Stephen King has a good idea. Castle Rock has been the setting for works including “Cujo,” “The Body,” and “Needful Things;” it’s the place to which King returns, again and again, when seeking a town whose name can serve as shorthand for the evil that lurks in small American communities.

Which would seem to lend a lot of promise to Hulu’s new horror series “Castle Rock;” we’re already primed to assume that anything can happen in a loose adaptation of King’s work, and are game to see King’s imagination outdo itself. (The novelist serves as an executive producer.) But while “Castle Rock” does a fair amount right, it’s ultimately a letdown precisely because of how much it uses its setting — the fact that we already know, and are repeatedly told, that the town is a wicked place — to communicate a sense of creeping dread without really doing the work. It’s eerie-by-the-numbers, repeatedly telling us quite how scared we ought to be, without yet building characters for whom we feel sympathetic fear.

Andre Holland, of “The Knick” and “Moonlight,” plays Henry Deaver, an attorney who had left Castle Rock. He returns after becoming embroiled in the case of a young man (Bill Skarsgard) found being kept prisoner, seemingly outside the bounds of the law, within a secret chamber in the local penitentiary. (It’s the Shawshank State Prison, naturally.) The lawyer’s past in Castle Rock precedes him; just about everyone he meets seems to recall an infamous incident that resulted in the death of Deaver’s father when Deaver was just a child.

Is Deaver himself an agent — if unwittingly — of darkness? Or is he simply unlucky enough to keep stumbling upon the wrong side of the ongoing battle between good and evil? Is his attempt to liberate a client who comes to seem safer kept as far from humanity as possible wrongheaded benevolence or something more complex? These questions haunt the enterprise, and the appealing Holland does his best to make us empathize with Deaver. The character’s history is engaging in its broad strokes: Adopted by white parents — his mother is played by Sissy Spacek — Deaver has plainly never fit into the world around him; he’s now attempting to help her in her old age, and she rejects his overtures. But too much of that backstory is delivered through undistinguished exposition, so much so that it comes to seem less richly textured in the way of the best King characters than simply piled on.

King, at his best, is a gorgeous writer, often making heavy meditations about the nature of good and evil soar on the page. But they’re hard to carry off onscreen — as proven by Hulu’s recent “11/22/63” — and much of the dialogue here feels flat and surreal, frustratingly removed from human experience for a show whose gory scares aim to be gut-punch visceral. At least “Castle Rock” gets pure evil right; the creature at the story’s center, Skarsgard’s unnamed prisoner, is quietly, docilely compliant until moments when he needs to demonstrate his malign power, as when he converts a guard from bragging about his willingness to torture to meekly running away with only a few moments of staring him down. A character is said to have discovered “the devil was a boy;” we come to believe it, thanks to a performance that’s yet more effective than Skarsgard’s own in last year’s “It” adaptation. That mega-hit film and “Castle Rock” have opposite problems; “It” was grindingly, thuddingly obvious in provoking the same scares over and over, while “Castle Rock” seems at times to rush past moments of tension.

King’s towns, including Castle Rock, glimmer with imaginative possibility thanks to their inhabitants. And yet most of “Castle Rock’s” residents leave no more impression than as familiar types: Scott Glenn as a seen-it-all sheriff, Jane Levy as a boldly outspoken young assistant who asks all the questions others are afraid to (and delivers some of the show’s most obvious pure exposition in the process). Melanie Lynskey’s neurotic realtor, haunted by a timidity that manifests itself in illness, is a bright spot, showing us a person who has been warped by life in a town where metaphysical danger is a fact of life.

Were every character written with the care that goes into Lynskey’s Molly Strand, “Castle Rock” would be a shimmering example of just how powerful — and well-suited to TV — King’s work can be. But too many of her neighbors speak in broad, platitudinous terms about what they’ve suffered through, or explain that trauma in unremitting chunks of unreal dialogue. What does it really feel like to live in a place where supernatural horror plays out? Disappointingly, it seems pretty quotidian. “Castle Rock” will surely attract some die-hards, but, sketchily unfocused on the human scale, it is surprisingly inhospitable to casual visitors.

TV Review: “Castle Rock” Drama series (10 episodes, four watched for review): Hulu, Wednesday, July 25.

Credits: Executive Producers: Sam Shaw, Dustin Thomason, J.J. Abrams, Mark Lafferty, Ben Stephenson, Liz Glotzer, and Stephen King.

Cast: Andre Holland, Melanie Lynskey, Bill Skarsgard, Jane Levy, and Sissy Spacek.

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