Fridge Logic
- Why the hell would you just fill in the evil pool with dirt? The ghosts can still swim through mud and yank someone down to drown. Fill it in with cement instead; it'll harden and nobody can fall in or be pulled in unless the pool's supernatural presence can somehow crack it apart.
- They could be planning to do that later; they're just starting with earth because it's easier.
- Why in God's name would you let your child swim alone, even if it wasn't a haunted pool? A substantial number of children die every year from accidentally falling into an uncovered pool or from being out there alone, getting a cramp, and drowning because there is no one to pull them out.
- Because the dad is already being influenced by the pool and obsessed with his health and career over anything else. The mom told him he could swim if the dad watched him. The dad said he would then didn't.
- Why did the pool ghosts not kill the son when he was swimming alone since it wants him in exchange for healing his father.
- They may require someone to give explicit consent for the "trade", and at that point the father hadn't properly realised what was happening to him.
- Why does the father menace and chase his daughter while possessed by the pool ghost if the pool ghost only wants his son instead?
- How does the son not drown if the mother had to go through such lengths to be able to swim to the bottom to possibly rescue him? His lungs are smaller than hers and he absolutely should have drowned since the pool ghosts want him dead anyway.
- Plot Armor. Having him survive allows the mother to have a successful Moment of Awesome and opens up the father to perform a Heroic Sacrifice.
- It could also be that the more benevolent ghosts such as Rebecca were able to keep the boy alive until he returned to the surface, on the grounds that the trade wasn't "complete" yet.
- Why does the sacrifice work when the dad voluntarily kills himself? It's supposed to take one life to give another, but it's just taking the same one that was given to it.
- It's still an equivalent exchange. Give one and take one. The pool took an ill man and made him healthy and then that healthy man was sacrificed. It can also kind of count as giving back the gift. The dad is dead and no longer benefiting from his renewed health so nothing is owed anymore.
- Why does the family choose to stay? They could've still filled in the pool with concrete and then left. They could also sabotage the house and burn it to the ground so it'll take a few years before anyone can move in and potentially get hurt if the cursed pool somehow regenerates or breaks apart the concrete they (should have) poured.
- They could have decided they will basically take responsibility for "guarding" the pool and make sure nobody else can use and abuse its power in future while they work to ensure nobody can access it again.
- Won't the police immediately notice the dad's disappearance and the pool being filled in shortly afterward? Wouldn't that immediately be obvious to check first? Even if they don't find his body, that would also give the pool yet another opportunity to drag someone down into it to die when the cops dig up the pool and search it for his body or signs of foul play.
- Most likely the family reported the father's death/disappearance and gave themselves time to establish an alibi before filling in the pool.
- Why do the pool ghosts take the cat? Is it because it was wary or maybe would have alerted someone or was it just being a petty asshole? And for that matter, would animal sacrifices work instead of people? In that case, technically speaking, the father could have yeeted a pigeon into the pool and gotten off scot-free instead of dying. It would be a shitty thing to do, but it would allow him to keep his family intact.
- The father doesn’t realize what’s really going on with the pool until the very end, at which point his son is dying, and he doesn’t have time to find an animal to sacrifice, even if he knew for certain that would even work.
