When a malevolent force invests the world with suicidal despair, a reluctant mother must protect her children as they navigate a path through the raging madness.

Gnostic horror with a folksy vibe, showing a peculiarly American view of life. The opening sets up a nice dilemma, of a protective mother so harsh that she risks destroying the very thing she loves. Then we swing into flashback with an energetic relationship between the lead and her sister, which crashes into a collapse-of-civilization sequence comparable to the remake of Dawn of the Dead. Good stuff.

Sadly, the survivalist scenes aren't as tight or well-written as in that zombie classic, and the pace does drag a bit, broken up by brief trips to the present. Plenty of action - the credits name more stunt people than actors - so maybe it needed some gallows humour to mix things up.

The performances are good, particularly the lead and the little girl, although it was disappointing that the lead's interesting art didn't inform her character. The editing is pretty brisk, and I think it's the occasional moralizing speeches that drain the energy. The music is subtle and effective - I see Trent Reznor was involved - but the plinky piano in the final scene is pure schmaltz. Also the most beautiful piece, a sonata by Haydn, is used to convey the critical descent into madness - huh? Shades of Dr Lecter in his cage with the Goldberg Variations.

Camera-work seemed fine, but had to deal with the difficulty of conveying the danger of seeing direct daylight - and so we end up with what you might call gauze-vision: not entirely convincing. And that's where the trouble lies, in a mistake of perception. When I say gnostic horror, I mean the story sets up a world beset by the evil whims of a mysterious force, with the plot showing a way to overcome it. This is supported by the fact the force originates from outside, in Europe and Russia, but it's plain that those scenes are a projection of American hysteria - attributing to others one's own faults, which fuels the delusion that one has only to reach inside for the necessary virtue in order to overcome. The unintended irony is compounded in a scene where the ornery Trumpishness of one character is confronted by plain-speaking liberalism, without recognizing that they are both the problem. And the overcoming is done in a folksy return to traditional values during an ascent to paradise through blindfolded faith, even as the evil continues to rage outside. Religious in the most unhelpful way.

TL;DR: America, the phone call is coming from inside the house.