Stillwater sends Matt Damon on a mission to Marseille to free his jailed daughter

► Stillwater is in UK cinemas from 6 August.

After the Oscar-winning fact-based investigative drama Spotlight (2015), Tom McCarthy’s latest returns to the narrative terrain of his previous indie titles The Visitor (2007) and Win Win (2011). Both those stories put a flawed protagonist to the test, taking them out of their comfort zone to present a sort of moral lesson to the audience. In the first case, it was aloof academic Richard Jenkins opening up to the illegal immigrants squatting in his New York apartment; in the second, it was hassled lawyer Paul Giamatti realising that mitigating circumstances don’t exactly excuse his breaking the rules.

This time Matt Damon’s Oklahoma oilworker is even further out of his depth, an exemplar of blue-collar Middle America travelling to Marseille, where his daughter (a convincing Abigail Breslin) is in jail for murdering her student girlfriend, yet continuing to protest her innocence – the echoes of Amanda Knox’s travails in Italy are clear, if unacknowledged. Everything seems set up for daddy to crack the case and win his daughter’s freedom, but given his non-existent language skills, limited outlook and history of substance abuse, prospects look dim.

What’s more noteworthy is that a character who seems to exemplify the Trump-voting demographic – not that he’s actually allowed to vote, given his criminal record – should be put centre stage and taken seriously by a liberal Hollywood filmmaker. Though McCarthy smirks at this hapless traveller at times, he allows us to respect his fierce resilience. Most striking, and Damon’s reined-in performance really pays dividends here, is the way the film delivers a telling appreciation of how being constantly told you’re a useless screw-up can – even when it’s at least partly true – build up a simmering sense of grievance and resentment. It’s certainly an encouragement to understanding.

Much is engrossing here, so it’s a shame the crime-solving plot proves a bit of a plod. The romance angle, involving a local actress and single mum played by Call My Agent’s Camille Cottin – intrigued and English-speaking – is a hoary old cliché too, though it is handled with a degree of discretion and bolstered by a marvellous performance from Lilou Siavau, wily, truthful and affecting as her eight-year-old daughter.

With a co-writing credit for Jacques Audiard’s regular partnership of Thomas Bidegain and Noé Debré, the French milieu comes across believably. But the script short-changes Breslin’s turbulent emotional trajectory – one late-stage monologue about shame and spiritual acceptance, which feels as though it should land as the film’s key insight, is in the event somewhat awkwardly wedged-in: we haven’t spent enough time with her to understand quite where it’s come from. There’s ambition and craftsmanship here, and a willingness to expand horizons for a mainstream American audience, but ultimately the strands don’t quite pull together.