Aftersun, starring Paul Mescal and Francesca Corio, is a subtle and complex investigation of post-divorce parenthood.

Charlotte Wells's movie ripples and shimmers like a swimming pool of mystery.

With remarkable confidence, she just lets her movie unspool naturally, like a haunting short story.

Aftersun is about childhood memories being worn to a sheen by being constantly replayed in your mind.

Throughout most of the film nothing very dramatic happens, and even when something important does happen, it is coolly unemphasised.

Paul Mescal is – as ever – excellent as Calum.

Soph and Calum have to share a double bed in their room because the travel agency messed up his request for twin singles.

There is no atmosphere of imminent transgression or doom or emotional upset.

They get on with their holiday cheerfully enough.

Their rapport is a marvel, as is the way they have been directed by Wells.

And all this is structured in terms of flashback via Soph's adult self with great flair, quite unlike the normal way this framing device is managed.