Outside a great plague "The Shred" robs people of their memories and selves to greater or lesser degrees. Society is reduced to little pockets of memory and understanding. The family don respirator hoods and take turns at standing sentry with a rifle. Trespassing 'forgetters' become compost.
One day a stranger comes who has not forgotten.
This whole thing has an "am I unexpectedly watching porn" vibe to it. It's not. It's not even particularly titillating: there are a couple of exceedingly mild sex scenes but somehow the whole thing has an air of fecundity.
The family are like a pseudo-Victorian cult with rituals and nursery style songs while swanning about in homespun and linen. The women's masks are made from bonnets FFS.
It's full of clumsy "if you don't remember it did it happen, if you don't remember who you are you can be anyone" musing and early on the little girl says her favourite animal is the snake Ouroborous, pointing to it in a child's book of animals.
I'm pretty sure most children's animal books do not have Ouroboros in. This tells you the kind of movie you're getting.
There's a strong hint of sixth form play about it.
It's not terrible but it's also trying desperately hard to be portentous and coming across a bit pretentious. 5/10 slow and so-so.