Katell Quillévéré’s film starts with a long, almost wordless opening. In the pre-dawn dark, teenager Simon (Gabin Verdet) sneaks out of his girlfriend’s bedroom and cycles down through his deserted hometown, before driving with some friends to the coast. With the light coming up over the ocean, they zip up their wetsuits, wax their surfboards, and plunge in.

Their experience of the world – being young, free, and handsome – is one perpetual wave-ride. It’s an experience that comes to an end when, on the way home, one of them falls asleep at the wheel of their van. Simon isn’t wearing a seatbelt. His life, which has freewheeled along so naturally, just… ends.

Not quite, perhaps. At the hospital it turns out that Simon is ‘only’ brain dead, which makes him the perfect candidate for organ donation. Indeed, there’s a middle-aged woman, Claire (Anne Dorval), who has the kind of cardiac problems solvable by transplant. Simon’s death can give her a new lease of life, allowing her to support her teenage sons (and maybe rekindle love with an old flame). Before that happens, though – before she can be granted this precious extension – a whole lot of life has to happen first.

This is the subject of Quillévéré’s film: the process of transplantation and everything that goes into making it happen (parents persuaded, paperwork completed, heart transported); but also, literally, life – what it is like to be alive, part of the world but also separate and inward, both the centre of the world and tangential to the stories of others.

This subject makes Heal the Living’s own story necessarily diffuse and scattershot. Quillévéré is interested in everyone involved in the journey of Simon’s heart, no matter how briefly, and is willing to spend at least a couple of minutes to deftly humanise them (Simon himself is granted a lovely flashback). Each character is imbued with idiosyncrasies that provide clues to a deep, dark sea of thought and feeling.

Some cynics have seen Heal the Living as a long advert promoting organ donation. Aside from pointing out that such a gripe ignores the film’s craftsmanship, you have to ask: what’s wrong with that? When life can be as tender and surprising as Quillévéré shows it to be, why not gift it to someone?