Do you find masking tape scary? Most people don’t. But then most people haven’t seen Under the Shadow.

In Babak Anvari’s 2016 horror film, masking tape fortifies windows from missile blasts, seals over cracks in walls and ceilings damaged by bombing, and sticks together the objects destroyed by a supernatural creature haunting the mother and daughter trapped in the middle of it all. It’s their pathetically fragile defence against all the terrors of the world.

The film is set in a block of flats in Tehran, during the war of the cities – a series of missile raids towards the end of the Iran-Iraq war in the 1980s. In one of the flats lives Shideh (Narges Rashidi) and her daughter, Dorsa (Avin Manshadi). Shideh’s husband, a doctor, has been called up to serve on the frontline. Shideh herself has just been forced off a medicine course for her activities as a student in the 1979 Iranian Revolution.

All around them the war is intensifying, and one day a missile crashes through the top of the block. It doesn’t explode but stabs down into the concrete, smashing a hole in Shideh and Dorsa’s refuge. Specialists remove the missile, but the hole remains. And the missile has brought something with it. This isn’t clear at first; the film is too smart to announce its monster in an obvious set piece.

Yet, gradually, Dorsa’s behaviour becomes more unusual, and she starts talking about the djinn, quasi-demonic spirits described by her new friend, a “mute” boy in another flat. Shideh is at first dismissive – she’s a woman of science, whatever the authorities say – but slowly it becomes clear that something is beginning to dominate Dorsa’s mind and turn her against her mother.

Denied the career in medicine her own mother longed for her to have, and torn between leaving or remaining in Tehran, the last thing Shideh needs is a spirit-creature claiming she can’t look after her own daughter. Under the Shadow is about this central worry. With the world collapsing around them, can mother and daughter stick together, even when forces from beyond reality threaten to tear them apart?

“Have you heard any strange noises around the building recently?” a neighbour asks Shideh at one point. How about any normal ones? In Under the Shadow, every noise that isn’t human is designed to creep us out. There are horror staples: screaming winds, shaking trees, shattering glass. There are those all too real indicators of modern conflict too: the constant rumble of background explosions, the demagogic ramblings of political radio broadcasts. And then there are the sounds so ordinary we wouldn’t normally notice them until their volume is cranked up to terrify us: the clatter of plastic toys, the churning of a Hoover, the peeling, ripping and sticking of omnipresent masking tape.

The effect is to make the implausible plausible. A film this serious about the social and political events it depicts should struggle to include what is, basically, a ghost. But Anvari’s genius trick is to embed the supernatural right into the material of everyday life. Not that “trick” is exactly the right word – it’s done with far too much subtlety and intelligence to be thought of as a gimmick. Stunning to think that this was the Iranian-born Anvari’s directorial debut.

It’s as if Shideh can’t even trust her most immediate physical surroundings. Which, of course, she can’t. Not the flat, not her daughter, not, it seems, society at large. When she manages to run away from the block with Dorsa, she’s soon picked up by the police. No hijab. “A woman should be ashamed of exposing herself more than anything else,” the police officer says, letting her go with a pardon. She could, apparently, have been lashed for this.

When another neighbour asks Shideh how she’s doing, about halfway through the film, Shideh replies: “Yes. I’m fine.” It’s the least convincing “I’m fine” in film history. But it does capture a resilience that I consider to be the film’s central message: the human spirit – and perhaps the female spirit specifically in this case – can triumph not only over its terrifying physical surroundings, but also its own worst internal nightmares.

It’s a noble message for a time when many of us have been facing a diluted kind of the claustrophobic paranoia Shideh and Dorsa experience. Mind you, at least we haven’t had jealous and terrifying spirits to contend with on top of it all. Small mercies, I guess.

• Under the Shadow is streaming on Netflix in the US and UK