Here’s a soapy, semi-harrowing wartime drama based on Ruta Sepetys’s bestselling YA novel Between Shades of Gray, about a teenage girl deported to a Soviet gulag. The book was written for teenagers but discovered by adults; the issue for the movie seems to be uncertainty about which audience is the target. It’s a sometimes hard-hitting, always heartfelt film – and star Bel Powley is an actor with an umami-style knack for adding depth to any film she’s in. But cynical viewers over 17 may find themselves rolling their eyes at snogs grabbed outside prison huts.

We start in Lithuania in 1941. Powley is 16-year-old Lina, a promising artist whose father, a university professor, is suspected of working against the Soviets. One night the entire family is arrested; Lina, her mum and little brother are loaded onto a cattle car and transported to a prison camp in Siberia. The commander, icily cruel Komarov (Peter Franzén), sentences them to hard labour in unbearable conditions – digging beetroot out of frozen mud day after day with their bare hands. The characters speak mostly English, though Russian lines are in Russian. There’s no other way around the language problem I suppose, but it is distracting; you can never quite forget you’re watching actors in pretend-dirty clothes talking English with eastern European accents.

The film’s pace flags a fair amount, but director Marius A Markevicius sensitively shows Lina’s humiliation and horror as a teenager in the camp. Arriving after weeks on a cramped train with no toilets or water, the prisoners are ordered to strip naked for washing. Lina is mortified by the prospect of getting undressed in public, especially since the boy she likes (Jonah Hauer-King), is standing nearby – in true YA style, atrocity and tragedy can only ever be a backdrop to an epic love story. Though to be fair, Markevicius doesn’t flinch from brutality: upsetting scenes showing prisoners being arbitrarily shot dead and an attempted rape scene more than earn the 15 certificate. A war drama with stabilisers.

• Released on 19 February on Amazon Prime Video.