Imagine the pool scene from Poltergeist stretched to a hundred minutes long.

After Ray Waller (Wyatt Russell) comes down with a career-ending illness, he’s terrified to admit his days as a baseball star are over. His wife Eve (Kerry Condon) coordinates moving between cities, dragging her family to new places to access the latest treatments. After Ray slips into a covered pool at a home showing, he experiences a vision of himself as a sports legend reborn… and his new doctor did recommend a pool for his exercises, right? Faster than you can say “we’ll take it,” the family of four settle in. Ray’s son Elliot (Gavin Warren) notices it first, followed quickly by daughter Izzy (Amélie Hoeferle) that something is wrong with the pool. By the time Eve suggests the family needs to leave, Ray is ready to resist… and it isn’t the first time the water has made such a promise.

At first glance, one might mistake this for a remake of some obscure Japanese horror instead of an expansion of a short film by filmmakers Bryce McGuire and Rod Blackhurst. Clocking in at under four minutes and starring Megalyn Echikunwoke, the short “Night Swim” lived up to its name, prompting Jason Blum and James Wan to greenlight a joint feature-length expansion of the creepy aquatic idea. With a script adding an “epic, supernatural mythology with a gothic fairytale undercurrent,” a cast was assembled and production began, plotting a release for the same first weekend of the new year that yielded the welcome success of M3GAN. The formula isn’t unfamiliar, a stressed-out family moving into a strange yet conveniently available home filled with ghostly promise that will end in a nightmare, preferably with a body count and a few Rube Goldberg-style “accidents.” Only two things are certain: there will be swimming — oh yes, there will be swimming — and the bad stuff only happens at night… right?!

While the cast works with what they have, the expanded elements feel forced right from the beginning. Dad can benefit from swimming; mom was diving before she was crawling; the son loves diving for coins off the bottom; the daughter has “the reach of a swimmer.” Gosh, we wonder why no one uses this wonderful pool anymore! There’s also the “everything is sinister” checklist, from the mandatory creepy pool tech to the clownish childish voices coming out of the storm side drain luring children with a paper toy boat. Even the underlying mythology feels like a discarded M. Night Shyamalan plot stocked with scraps from Stephen King stories — hell, let’s even throw Ron Howard’s Cocoon in — but none of it as interesting as the original short. Nothing even exclusively happens at night, so the title would have made more sense to just call it Haunted Swimming Pool.

There was some potential in the overall idea, but better elements were abandoned for building the scary-dad angle we’ve seen in The Shining, Sinister, Insidious, and Frailty. The “Night Swim” short appeared to be set at a run-down motel, and while a family staying there might be vulnerable, what if we explored the woman there alone? Imagine the pool was actually an empathetic creature, acting on its own to protect against perceived threats, or at least take advantage of a free meal. Perhaps our heroine had finally left her abusive lover, having checked into the motel only to for him to have follow her; the scene we’re treated to in the short is actually how the pool hides her away. When the abuser stomps out to the pool area knowing she might be there: “Wait, you’re not her!” (cue false shadow woman and drowning noises). Our heroine reappears in the again-empty pool, noticing half an hour has gone by while she must have been underwater. How is that possible?! The cops respond to the manager’s 911 call about some guy raging to know what room his girlfriend was staying in, but he seems to have left and hasn’t been seen since… or ever again. Fun post credit scene: an empty pool and a loud burp. Make it an anthology!

Not every short film idea works as a feature. Take last year’s Skinamarink, the long form of which had viewers peering into darkness waiting on boo-scares that never happen, an exercise in attentiveness without any payoff (but a surefire cure for insomnia). Night Swim goes to the opposite extreme, padding a interesting idea with so many borrowed elements that even the uniqueness of the short was lost in translation. Even the guys who made Talk to Me understood eventually there has to be a “there” there; maybe that’s why the pool was abandoned to begin with, hmm?

Night Swim is rated PG-13 for terror, some violent content, language, and not holding your breath it gets any better.

One skull recommendation out of four