Despite its starry names like Trainspotting’s Jonny Lee Miller and Sex Education’s Tanya Reynolds and a deserved West End transfer, A Mirror is an intriguing prospect for two bigger reasons. The first is that Sam Holcroft has crafted the best Orwellian work since 1984 and, secondly, she has created a production which in terms of immersive theatre stands head and shoulders above supposed confreres like Cabaret and Guys and Dolls.

Holcroft isn’t one for writing “normal” dramas or for churning them out at a rapid rate.Her last outing was 2015’s Rules For Living, headed by Stephen Mangan. An apparently prosaic setting of a family sitting down for Sunday dinner is turned on its head by a couple of inspired touches. Over the cast’s head, a lit scoreboard shows the inner traits of each character (for example, one can only make a joke while standing up and another uses accents when mocking someone). The drama and comedy come to a head not with a group hug but with an almighty food fight at the end.

A Mirror similarly upturns expectations throughout. Everything is set up to seem as if we in the theatre are attending a wedding: flower arrangements are set up all around the venue and on stage, the seats all have a guide to the ceremony and the happy couple are seatged and holding hands while the best man paces around and a black-gloved priest gazes upon a book.

The first inkling that we are not about to witness some standard nuptials comes from the guide which indicate that we are in a fictional state and will be asked to pledge allegiance to the authoritarian leaders. After a few minutes, the priest reveals that we are not here to witness a matrimony but a player; in fact, we are not wedding guests but collaborators in an act of illegal theatre. Toto, I've a feeling we're not in Kansas anymore.

From there, things move fast and we go from watching a play about a play to disappearing Inception-like deeper into a rabbit hole of auto-fiction. Holcroft holds us for two hours without interval in the palm of her hand as she unravels a bewildering plot around a car mechanic whose stunningly accurate work is championed by a senior culture minister while both fight for the heart of the censor’s assistant. The ending piles another twist on top and features a face familiar to those who saw another immersive show about the power of controlled thought last year.

As the minister Celik, Miller is supreme and provides the kind of acting masterclass that belies his meagre stage experience over the last decade. His stint on the US show Elementary has gained him a spot in the Guinness book of records as the most prolific Sherlock Holmes ever and some of his mannerisms from his depiction of the detective - twitching, strident, arrogant - carry over here. Reynolds plays junior Mei with verve and vigour opposite Samuel Adewumni as Adem’s mechanic. Jeremy Herrin’s direction is confident and pacy, despite the outsized running time.

The Playhouse’s Cabaret and Guys & Dolls at The Bridge say they are “immersive” but these claims are skin-deep at best; it takes more than a few actors dotted around a venue and a moving stage respectively to make us feel throughout that we are in a different time and space. A Mirror works hard to fold us into the drama from the beginning with a payoff in the final scene: when the cops do inevitably show up and flash their torches into our faces, we feel genuinely scared and wonder how far Holcroft will take this. Should we be holding up some kind of ID? Will we be detained until after the last tube departs? Or should we prepare to pay some form of penance?

There are, of course, more interactive and more fun immersive experiences around London and beyond. The audience has little agency but, in some ways, this is part of the truth being laid out here. Freedom is forever defined by the boundaries set upon it and by those who set the boundaries. Whether we are in a dictatorship or in a theatre, we are prisoners to the thoughts and ideas of others.

A Mirror continues at Trafalgar Theatre until 20 April.

Photo credit: Marc Brenner