There are worse ways for a television star to transition into film than a horror movie. There are also better movies to do it in than The Boy. Still, Lauren Cohan of The Walking Dead shines bright in William Brent Bell’s dim genre exercise, a vital presence opposite a lifeless co-star. She plays an American nanny who, upon arriving at her new employers’ rural English abode, learns that her eight-year-old charge is actually a life-sized doll. The real Brahms, we're told, died under cloudy circumstances some 20 years earlier, and this porcelain facsimile has taken on the role of a physical and emotional stand-in for the elderly parents — like many (if not most) horror films, The Boy is a case study in how not to deal with grief.

In these early scenes Cohan seems poised to elevate this silly premise, showing an unusual talent for small talk and other casual interactions that ground the fanciful story. More than most would-be scream queens, Greta comes across as an actual human being, making it impossible for audiences to write her off as cannon fodder. There’s only so much she can do once the movie around her devolves into the usual barrage of jump scares, but Cohan maintains her composure even as Greta loses hers.

On the strength of that performance, The Boy often feels more credible than it has any right to; in merely keeping a straight face and not betraying how patently ridiculous this all is, Cohan makes us hold our breath along with her during the small build-up scares, as when items of clothing go missing and a child’s laughter echoes throughout the house. There are only a half-dozen or so speaking parts, with Greta and that inanimate (or is it?) object getting more screentime than everyone else combined.

It helps that, as jump scares go, you could do worse than Greta catching in a mirror the unexpected sight of this genuinely unsettling inaction figure staring at her reflection: the porcelain expressionlessness, the silence all around it. This is a cavernous estate, full of dusty tomes and buried secrets, making it all too easy for Greta to fill the empty space with troubling thoughts that may not be as outlandish as they initially seem. For some weirdos (but totally not me), simply standing near a mannequin for too long makes you uneasy, so there’s an elemental creepiness to that dynamic — it’s impossible to look at Brahms without wondering when (not if) he’ll do something that a doll shouldn't.

At both their best and worst, horror movies have the power to make you wonder why you decided to subject yourself to 90 minutes of vicarious terror in the first place. The Boy never reaches either extreme, mostly arousing curiosity as to whether Brahms is a friendly or malevolent presence. The final reveal, though shocking in the moment, is the kind of skeleton that should probably have stayed in the closet.