So what else is there to the premise of "Night Swim" beyond "What if a pool was haunted?" Well, it also asks "What if a pool cured multiple sclerosis and made you amazing at baseball?" Ray Waller (Wyatt Russell), the patriarch of the family moving into the house with the haunted pool, was a professional baseball player before being diagnosed with MS. Presumably curing his disease returns him to a prior state of amazingness, but I wonder if the pool added some extra supernatural skill. The one scene we see of him at bat post-spooky magic (one of the only scenes in the movie that's not centered around the pool) makes him come across as basically a "Twilight" vampire.
Ray loves the pool, attributing his healing to the benefits of "water therapy." His wife Eve (Kerry Condon, slumming it post-Oscar nomination for "The Banshees of Inisherin") and kids Izzy (Amélie Hoeferle) and Elliot (Gavin Warren) are a bit warier of the signs this pool is bad news. Any way you could expect to see a ghost depicted in a horror movie — regular person but see-through, elaborate skeleton makeup, hideous blob of CG particle effects — you'll see in the haunted swimming spot at some point.
What you won't see is much creativity in how these ghosts kill people. It's a limited premise already, given there are only so many ways you can kill people using a pool as your weapon of choice, but there's zero excitement just seeing people being tempted by objects in the pool and then pulled underwater. Horror movies don't need gore to be effective, but when the material is this flat and lacks any convincing psychological terror, not even getting the shallow pleasures of cinematic violence makes this a nothingburger of a movie. If the reasoning behind making "Night Swim" PG-13 was to appeal to kids the way "M3GAN" did, it would help if the child characters here had any interesting traits whatsoever: the extent of their characterization is that Elliot's lonely, Izzy's boy-crazy, both siblings are jerks to each other, and neither is remotely worth caring about.
