Screening at this year’s London Film Festival, Brother’s Keeper is an undeniably hard watch. Director Ferit Karahan’s portrayal of childhood in a Turkish boarding school is harsh, unforgiving, and laced with a toxic, oppressive patriarchy where all suffer. But at its core is a tender tale of relentless loyalty, childhood tenderness – and above all, guilt.

The film follows Yusuf (portrayed with touching vulnerability by Samet Yildiz), a pupil at a remote, all-boys boarding school in Turkey. With a snowy storm rolling in and leaving the school isolated in the hills, it’s a setting entirely detached from civilisation – which becomes an issue when Yusuf’s friend Memo (Nurullah Alaca) falls ill of an unknown ailment.

What follows is a tense, desperate scramble to decipher the cause behind Memo’s sudden decline in health, and a race to get the help he needs in such desolate conditions. As such, it’s a gripping watch that breezes past its 90-minute runtime. Karahan paces the film with such precision, almost feeling like a play at points: he introduces characters steadily and purposefully, with each new entry into the quest to save Memo adding a new layer of nuance. Some members of the faculty genuinely want to help Memo; others are there purely to cover their own backs, sweeping away their secrets.

Yet even more than an intensely watchable thriller, the setting and context behind Brother’s Keeper is equally fascinating. We never learn too much about the boarding school Yusuf and Memo go to — who sent them there, how they became friends — but Karahan captures the toxic atmosphere poisoning the pupils from within. Unruly students are whipped, slapped, forced to bathe in freezing water, and have their heads shaved – and it creates such a claustrophobic atmosphere, with these regimented, authoritarian acts occurring in a place where the boys simply cannot escape.

It makes Brother’s Keeper a two-pronged double-punch of cinematic quality. You’ll be gripped both by the character-driven, convincingly performed plot, and the seeds of brutality and injustice that lie within the setting. It captures the ceaseless tug-of-war between childhood liberty and innocence against a landscape that is so biting in its oppressiveness, with thematic ideas just as interesting as the main plot. It’s not often a film can strike that balance with such panache: but Brother’s Keeper proves its worth on many levels.