Like the best science fiction, the premise plays stronger than it sounds: after an apocalypse has devastated and stranded the city of Chicago, a curious new society has evolved, consisting of five ‘factions’: Abnegation, Amity, Candour, Dauntless, Erudite – each representing an essential personality type. In an annual ceremony, 16-year-old citizens choose which faction they will belong to for the rest of their lives.

We follow Beatrice, daughter of Abnegation parents, who after her ambiguous (‘divergent’) aptitude test, surprises even herself by deciding to leave her birth-faction and join the Dauntless (or ‘suicidally reckless’) crowd. But as she struggles to prove herself dauntless, dark things are going on elsewhere in society.

The film plays to its strengths. It’s really the story of a teenager who abandons her old life to start a new one – an adventure, in short. And that’s what it feels like for the bulk of the film’s running time. The director does not assume we want to skip all this stuff about bonding and self-discovery and fast-forward to the action set-pieces – we don’t, and we’re not forced to.

But the film’s biggest strength is its star, Shailene Woodley (previously seen, by Film Group audiences, in The Spectacular Now last semester and in The Fault in Our Stars earlier this semester) – who manages to simultaneously project kind-heartedness, uncertainty and just enough strength for us to believe in her heroic qualities. She almost never leaves the screen, but we always want to watch more of her.

The story is split into four seasons. We open with summer. Isabelle has just turned 17, and is on holiday with her family in the south of France. She has a summer fling which, to understate the case, does not work out well – which may have a strong influence, or no influence at all, on what follows.

In autumn, Isabelle is back in Paris – and we find she has turned to prostitution outside of school hours. Why? We’re never really told. She doesn’t need the money, and her relations with her family are no worse than any other teenager’s. Marine Vacth, the actress playing her, has said in an interview that Isabelle ‘turns tricks the same way she might have tried drugs… to confront the world around her, figure out who she is’. I’ll accept that, but state it even more simply: it’s just one of those things. Maybe I’ve simply imbibed the film’s existential outlook. It sometimes seems from their movies that the French will phlegmatically accept pretty much anything. (Don’t you love them for it? I do.)

At any rate, Isabelle can’t keep her secret hidden forever, and winter and spring detail the consequences when her family finds out. Like most of what’s happened so far, it won’t be quite what you expect. The film has no twists, exactly, but quite a few turns – at least once per season, we take a side path to a place more intriguing than where we thought we’d end up.