Relic

  Relic (not to be confused with The Relic, a 90's horror movie that like a lot of '90s horror is pretty crap) tells the story of Kay (Emily Mortimer) returning to her old family home with her daughter Sam (Bella Heathcote) after she's informed her mother has gone missing.

 Grandma Edna (Robyn Nevin) lives alone in a large house in the woods and has a history of dementia. When Kay and Sam arrive at the house they find it recently abandoned and hunker down to either wait for Edna to return or to get some pretty grim news at night, and help with the police search during the day.
 Beyond all the mundane creepiness of an inhabited but slightly run down old house, there's also some hints of unnatural goings-on: strange sounds coming from behind the walls, shadows lurking along the edges of the frame... you know, subtle, haunting-style stuff.
 Kay also has a nasty nightmare about an old cabin with a withered corpse. This will become significant later.

I'm not a fan of the book, but after watching this I'd love to see Natalie James take on House of Leaves

 Edna returns after a few days, not much worse for wear, in a nightgown and sporting some new bruises. Sam and Kay decide to stay a couple of weeks with her to keep an eye on her. They also have some difficult choices ahead as to how best handle the situation.

 Cohabitation is difficult beyond the already fraught situation. Edna doesn't just forget things - she's sometimes difficult, even hostile towards her daughter and grandchild. But as these difficulties escalate, the strange incidents do as well, until the movie jumps the rails in the best way possible. What was a pretty low-key psychological horror film... well, remains a psychological horror film, but earns the batshit adjective. It includes impossible architecture and a monster chase; Way more fantastic than the slower, more buttoned-down first two acts would lead you to expect, is what I mean; Subtlety goes out the window.
 I adore it when movies surprise me like that. Even better when a) the movie was a good one to begin with, and b) it sticks the landing. Here, after some pretty cool mayhem, the script pulls a U-turn and ties everything together in a bittersweet and pretty affecting ending. Lovely stuff.

 While the horror elements seem a bit random at points, they are very effective at building up atmosphere and make thematical sense. And even without them, well, dementia is pretty fucking horrifying. Relic doesn't offer the most sensitive look at mental health issues, but it's very empathetic and uses them in a way that ultimately doesn't feel exploitative. Natalie Erika James' direction is top-notch, with lots of great suspense building and careful framing, and it gets a lot of mileage out of what must have been a fairly small budget.
 Honor compels me that this was helped reach production by the Russo brothers (along with Jake Gyllenhaal, of all people). Well done Russo Bros. You've still got a lot to make up for.

  This is a great movie - very well made, phenomenally acted, and with an excellent story in its black-mold-infested heart.