The Encounter, Bristol Old Vic

Complicite have, for several decades, been Britain’s most consistently adventurous theatre company.

The term "physical theatre" sells them short, for the intelligence of their shows, from The Street of Crocodiles to The Elephant Vanishes, The Three Lives of Lucie Cabrol to Mnemonic goes far beyond a spectacular use of the human body and the endlessly inventive use of props and space.

The Encounter, a wholly extraordinary one-man show by the company’s co-founder Simon McBurney, is all of these things, but a good deal more. This is a show that re-invents theatre with a brilliance and sense of delight that never succumbs to gimmickry or a self-congratulatory display of technique. It also delivers a deeply moving and thought-provoking punch, raising questions about our perceptions of time and our apprehension of reality.

The piece is based on Petru Popescu’s Amazon Beaming, a riveting account of the American photographer Loren McIntyre’s experiences while lost in the upper reaches of the Amazon, near the Peruvian border, when he is rescued by a stray band of Mayoruna, a group intent on avoiding contact with the predatory white men who have invaded the oil rich forest. None of the tribe speaks any Spanish or Portuguese, but something happens that McIntyre at first cannot quite believe: one of them seems to "beam" thoughts to him in a kind of telepathy.

McBurney takes us on a journey into the Amazon, but in our minds. The audience are provided with headphones. We hear McBurney live, his voice deepening when he plays the American explorer, or raised in pitch when he impersonates Cambio, a Portuguese-speaking Mayoruna he meets later in the story. In addition there are a number of pre-recorded voices skilfully mixed and making imaginative use of the stereo effect of headphones.

 Good theatre has always been about the suspension of disbelief, in other words about enchantment

This paradoxically enables both distance and intimacy, creating immersive theatre that retains a framing device without which theatre would lose its magic. In a high-wire act of storytelling that conjures a series of worlds and yet keeps us questioning them, McBurney plays himself, McIntyre and a host of other characters. Good theatre has always been about the suspension of disbelief, in other words about enchantment. This show messes with our minds in a near-miraculous way, as if we were on a hallucinatory journey, in which we are freed from the usual reference points that keep us safely within the confines of everyday reality and slip into an awareness of the fundamentally fictional nature of the world around us. I have never felt so tangibly that "we are such stuff as dreams are made on".

What is so exciting is that the content of the show – a white man’s discovery that there are multiple ways of imagining the world, that these fictions are the only reality we have, and that so-called "primitive" people know this –  is matched by its mutlifaceted form: we are moved by the experience, in the here and now, of the cascade of events that we witness on stage, while simultaneously exploring the wealth of ideas that McBurney has teased out of Loren McIntyre’s mind-expanding experience in the forest.

There is pitch-perfect mastery about every aspect of the piece: magical lighting, an array of individual sounds and constantly shifting aural perspectives, and the stunning range of ways in which McBurney moves seamlessly but always dramatically from one world – inner or outer – or plays with the notion of multiple subjectivities, using brilliantly conceived interventions from his six-year-old daughter or shards of insight from his friend the mathematician Marcus du Sautoy.

McBurney's marathon performance is a feat of endurance, but also a display of magical shape-shifting, as he moves seamlessly between identities and an array of body languages. He takes us through the terrors of darkness on the forest floor, at the mercy of "man-eating" maggots, and deep into the rituals of the Mayoruna. The intimacy of the headphones, a brilliantly appropriate idea, enables communication of a very special kind – in resonance with the worldless "beaming"  or "old language" of the Mayoruna people.

For all the entertainment that the show delivers, The Encounter also sets us thinking about the tragic downside of our insatiable acquisitiveness and greed, and about the way in which our addiction to material things prevents us from experiencing the flow of life and our connection with nature. A show which combines a deeply political message with a re-awakened sense of wonder is a rare thing. The Encounter overwhelms on every score.

• The Encounter is on at  the Warwick Arts Centre on 10 and 11 October 2015 and the Barbican, London from 12 February to 6 March 2016