Following in the thematic footsteps of Jennifer Kent's 2014 chiller The Babadook, but with a cultural identity all its own, the debut feature from British-Iranian writer-director Babak Anvari – recently submitted as the UK's foreign-language Oscar contender – is fraught with tension and rife with intelligent insight. Using post-revolution, war-torn 1980s Tehran as its fractured backdrop, Anvari and lead actress Narges Rashidi create a slow-burn horror that pulses with paranoia and slowly descends into abject fear.

Rashidi is Shideh, a mother left alone with her young daughter Dorsa (Avin Manshadi) in her Tehran apartment after her husband is drafted to the front-line. After a bomb tears the roof off the building and Dorsa begins to grow increasingly disturbed, Shideh comes to believe an ancient evil entity has attached itself to their lives.

Anvari's perfectly pitched screenplay weaves elements of the traditional, the supernatural and the political to drill down both into the deep-rooted fears of the time – from the ever-present threat of conflict and death, to the extreme social laws that left women voiceless – to Shideh's own psychological distress, without ever becoming polemical or overwrought.

Under the Shadow is buoyed by an incredible performance from Rashidi, who plays Shideh as a thoroughly modern woman – at least, in the privacy of her own apartment, where she smokes and does a daily workout to a contraband fitness video. She is obviously struggling with the subservient role that society forces her to play and this frustration, together with her fear that she is not a good mother, seems to be intrinsically linked with the frightening events that occur with increasing regularity in the apartment.

Indeed, it's unclear throughout whether Shideh is really being haunted or is just losing her grip on reality, and it's to the credit of both film and performance that this question goes deliciously, uncomfortably unanswered until its truly terrifying basement climax.

Selected release from Fri 30 Sep.