Her boyfriend is the broad-shouldered, square-jawed Bin, the trusted lieutenant of the area’s biggest property developer and club owner. But a new generation of hoodlums is snapping at his heels. When a crowd of them attacks Bin in a crowded street one night – their weapon of choice appears to be garden spades – Qiao saves his life by firing his unlicensed pistol in the air. She then swears to the police that the gun is hers, so Bin gets out of jail after a year, and she has to stay in for five. But neither he nor any of his fellow gangsters rewards her loyalty. He is nowhere to be seen when she has served her sentence, so she ventures down the Yangtze River to find him, determined that they should be reunited.

Ash is Purest White delivers its share of gangster-movie thrills. Jia builds the tension mercilessly when Bin and Qiao’s car is surrounded by thugs on motorbikes, and then releases that tension with a brutal martial arts dust-up. Later, when Qiao goes in search of Bin, the film becomes a funny, feminist revenge caper. Refusing to be defeated, she proves herself rousingly adept at conning, stealing and threatening her way around a remote town, equipped with nothing but her wits and a plastic water bottle.

But these generic pleasures are just one part of a long, digressive odyssey which ranges from 2001 to 2018. Often shot in pale natural light, Ash Is Purest White comes to feel like a mythical tale of a spirit wandering the afterlife or an astronaut lost on an alien planet – and that’s even before Qiao bumps into a man who says that his travel agency specialises in UFO-spotting tours. A mangy lion and tiger make an appearance, and there are several ballroom, line-dancing and disco interludes: The Village People’s YMCA crops up again and again, just as The Pet Shop Boys’ Go West featured in Jia’s last film, Mountains May Depart.

But the theme that emerges is how relentlessly the world keeps changing. People age, relationships wane, crime syndicates fade, and China itself mutates as cities are redeveloped and the Three Gorges Dam puts miles of countryside underwater. Few film-makers are as observant or as poetic as Jia is about the passing of time: building sites and smartphone technology are particular obsessions. And Zhao – Jia’s wife – responds miraculously to the acting challenge, transforming herself in subtle ways so that Qiao becomes harder yet more exhausted as the years grind by.

Towards the end of the film, though, you may feel as if you’ve aged almost as much as Qiao has: I certainly wouldn’t have minded if it had been half an hour shorter. You may also ask if Bin is worth all of Qiao’s efforts, and whether she shouldn’t just forget all about him. But, of course, she can’t. Despite all the evidence to the contrary, she hangs on to the conviction that while everything else around her is decaying, love is eternal.

★★★★☆

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