Stranger Things: The First Shadow review – breathtaking theatre

It starts with those floating red letters and that electro-ethereal music. The intro creates the surreal effect of Netflix’s sci-fi juggernaut being brought to life as a stage-sized facsimile before our eyes. But the big surprise about this prequel to the TV series, about high-schoolers who tap into the dangerous world of the Upside Down, is that it is neither derivative nor an exercise in imitation. This is breathtaking theatre with its own arresting imagination.

With an original story by the Duffer Brothers, Jack Thorne and Kate Trefry, we are still in Hawkins, Indiana, where pets are mysteriously dying, but the year is 1959. Writer Trefry takes a flashback from the fourth season of the 1980s-set series and turns it into a typically complicated plot, although my 10-year-old companion (the guidance is for 12+) had no problem following it.

The production has the same sense of sprawling mystery, beginning with the disappearance of a wartime naval ship and a laboratory experiment that explains the birth of the Upside Down. There is no Eleven yet but Henry Creel (Louis McCartney), the new kid in town, brings dark powers. He has an oddball romance with Patty (Ella Karuna Williams) and a sinister relationship with Dr Brenner (Patrick Vaill).

There is speed, action and scale, with one coup de theatre after another and immense craft in Stephen Daldry and Justin Martin’s co-direction. A quotidian reality of high-school hallways and toilets morphs into eye-popping alternate worlds. These switches happen in seconds, the gothic returning to the ordinary on Miriam Buether’s nimble set. Jon Clark’s stunning lighting switches between sinister and sunny, while characters transform with it. There is a dazzling doubling to this, which adults might read as split selves while kids will merely find thrilling.

It is truly dark too, with horror film jumps and menacing gurgles (great sound design by Paul Arditti), contrasted with a bright-eyed, retro Americana laid on thick and smatterings of song.

Even if you can’t keep up with the plot, it is underpinned by serious inquiries into the psychopathy of war, toxic inheritance, and the search for good parents and release from bad ones. It also touches on othering and adolescent anxieties about being “normal”.

Related: The West End turns upside down … Stranger Things: The First Shadow – in pictures

The show has fine, fleet acting too. Joyce Maldonado (Isabella Pappas) has not yet made her mistakes with Lonnie (Chase Brown) and is full of fire. The swaggering James Hopper Jr (Oscar Lloyd), who will later become the town’s police chief like his father, gets embroiled in the central investigation with Joyce and Bob Newby (Christopher Buckley).

Those familiar with the series will be able to trace storylines back but the production is not just a clever parlour game for fans. If you come at it afresh, it is still irresistible. A spurt of lazy film-to-stage adaptations have recently hit the West End but this parallel world is a winner.

• At Phoenix theatre, London, until 25 August