While it may be set in 1993, this adaptation of Emily M Danforth's 2012 novel The Miseducation of Cameron Post has a devastating modern resonance. An understated yet powerful portrait of identity, sexuality and acceptance set against an immovable religious backdrop, it's a sobering reminder of the systemic prejudice that accompanies those who identify as 'other'.

Chloë Grace Moretz is outstanding as the titular Cameron, who is shipped off to an isolated Christian camp after she is discovered being intimate with another girl in the backseat of her boyfriend's car. For Cameron and her fellow 'disciples', who include the wonderfully named Jane Fonda (Sasha Lane), so follows weeks of conversion therapy intended to cure them of the 'sin' of same-sex attraction.

While it's impossible not to draw parallels between Cameron's experience and that of the wider LGBT community today, director Desiree Akhavan (Appropriate Behaviour) resists any polemical exploration of the issues. Instead, she focuses on the small, everyday details: one of Cameron's classmates has his long hair shaved off by stern leader Dr Lydia Marsh (Jennifer Ehle); another reads a letter from his father expressing disgust at his feminine ways. These small, terrible acts chip away at these impressionable youngsters, eroding their confidence, happiness and sense of self.

The strength of the film comes largely from Akhavan and fellow writer Cecilia Frugiuele's reserved screenplay, which treats all the characters with empathy and avoids the melodrama and cliché that could have so easily come with this 'pray away the gay' territory. Performances, too, are excellent across the board, with Moretz's subtle strength and Lane's resigned sarcasm helping balance the darker themes of the narrative. (That Jane hides weed in her fake leg is a brilliant touch).

Still, there's no denying the film's impact, and its lasting message. While Cameron and Jane are strong and tenacious enough to survive such an experience, so many others quite simply are not.

Screened as part of Sundance London 2018. General release from Fri 7 Sep.