© Drew Farrell

It's not often that a play really achieves a new form – but Flight, part of Edinburgh International Festival and created by Vox Motus, genuinely does. An adaptation of Hinterland, a novel by Caroline Brothers, it tells the story of two brothers travelling from Afghanistan to England through a series of exquisitely crafted dioramas. Each audience member sits in a private darkened booth, as tiny static 3D scenes in boxes slowly scroll past in front of them; through headphones, we hear of 15 year-old Aryan and eight year-old Kabir's journey, both traumatic and hopeful.

As a piece of theatre, well, it isn't live and it isn't communal – but it is effective. Think of it more like reading a comic book, but with an aural, acted soundtrack rather than speech bubbles. There are cinematic shifts in perspective: here a close-up on an anguished face, there a long-shot of a beautifully back-lit orange grove. Indeed, Simon Wilkinson's radiant lighting is totally gorgeous throughout, illuminating the delicate figures and models made by designers Rebecca Hamilton and Jamie Harrison (the man who also, in quite a leap of scale, is responsible for the illusions in Harry Potter and the Cursed Child).

The attention to detail is just lovely: I lean forward and peer enraptured at displays of minute cakes in patisserie windows or slender-branched trees surely almost trembling with tiny leaves, for all the world like a greedy child in a doll's house shop. Only this isn't just cutesy: it's precise right down to littered cigarette butts, or the hanging carcasses in a refrigerated lorry in the Calais jungle – something Sylvanian Families sure never scaled down.

And Flight is about more than sheer technical skill: it's a story that needs to be heard, a journey that we need to go on with Aryan and Kabir. In a way, it's very simple: the brothers walk, getting through seven countries and seven pairs of trainers; they travel on trucks, boats, buses, trains, and encounter people that will abuse them, and – more rarely – that will help. A little light symbolism is woven throughout: birds begin as something to envy, free to fly rather than trudge, and appear as wistful, ghostly white etchings in the boys' dreams. But later, gulls also morph unnervingly into squawking, incomprehensible, aggressive border guards, wielding guns. They can stop the brothers' flight, clip their wings.

It's horribly, shamefully easy to feel like we've heard this story already, to suffer from sympathy fatigue when it comes to the migrant crisis. Yet in matching an almost twee craft with an account of the horrendous, inhumane treatment of two very young men, Flight makes the story feel newly fresh. It's miniature, yet also epic – which proves a considered way to convey a humanitarian crisis that we know is made up of individual stories, yet can still feel overwhelmingly vast.

Flight runs at the Churchill Theatre and Studio until 27 August, times vary.

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