Horror/thriller???? SOLVED
I dont really remember much, but it's American and from the last 10 years I'd say, maybe a bit more 🤷♀️
Near the start there's something about a girl (I think, could be a boy!) Visiting their family home. As a younger child one of their parents had died or vanished.
This house had a pool, it's important to the story but I can't quite remember the details of it.
This person later goes into the basement (underneath the pool) for some reason and there's a wall at the back made from glass.
They turn a light on and the missing parent is in there. Kept in there all these years by the other parent. I don't remember which way round it was, sorry.
Then later there is something about flooding the basement with the pool water to set the parent free.
I wouldn't say it's a great film, just normal Hollywood teen horror but it's just popped in my head and now I'm curious.
Any ideas ?