Chekhov’s last play, The Cherry Orchard (1904), is sometimes referred to as the first ecological play – informed by the playwright’s witnessing of the destruction of carefully nurtured and preserved landscapes, including his own beloved cherry orchard, all in the name of ‘progress’.

A century on, ecological theatre has moved towards environmental art, with a steady growth in outdoor performance centred around journeying that frames the natural environment as artwork.

One such piece is Rachel Henson’s Flickers: Off the Path which takes its participants on a guided journey through Stanmer Park (less a park than a glorious swathe of Sussex countryside, incorporating an 18th Century village and farm). The ‘guide’ is a series of flicker books which offer clues to the trail, and provide a counterpoint to the live experience by creating a filmic alternative reality, in which the same landscape is occupied by an enigmatic ‘other’, a red-headed ghost girl who is there in our flicker books – jumping walls, peeping through branches, and (ominously) driving a tractor towards us – but an absent character from the ‘story’ of our walk. Like all good walking-as-art pieces, Flickers teaches us to look again at familiar things (Trees! Stones! Nettles!); to re-evaluate our relationship with our environment; and to understand that walking beside us on every step of every journey we take are a host of ghosts – products of our own memories and imaginations, and resonances of everyone else who has walked this way in other times. You never walk alone…

Walking back, we pass the cherry orchard (in full bloom!) and Stanmer House, the site for Dreamthinkspeak’s beautiful and haunting Don’t Look Back, commissioned for Brighton Festival 2003. For this year’s festival, Dreamthinkspeak take the cherry trees indoors in Before I Sleep, less a ‘version of’ than an ‘homage to’ The Cherry Orchard set in the derelict Co-operative department store on London Road, an area of Brighton that has been tipped for redevelopment for many a year. Chekhov’s tragi-comic turn-of-the-century tale of the forces of change in battle with the status quo – played out around the auctioning of a family estate and subsequent destruction of a cherry orchard – transposes beautifully to a story of the doddery old guardian of a department store (the manservant Firs elevated to lead character in this reinvention) wandering his ‘manor’ in a sleep-deprived daze, terrorised by the onslaught of modern consumerism, which bursts upon his shadowy and musty world with alarming brightness and brashness.

The show is a carefully-orchestrated promenade performance in which the audience are led by sound and light through the building, encountering snippets of the play’s narrative, echoes of its themes, and evocations of its characters and actions – the whole building framed as ‘the estate’ (literal interpretation) but also providing a metaphor for the central theme of ‘do nothing’ decay versus aggressive regeneration (a theme that perfectly befits the dearly beloved old Co-op building, once the heart of this run-down shopping area).

Those who know Dreamthinkspeak’s previous work will be unsurprised to learn that Before I Sleep makes very good use of film installation, employs lighting and music creatively, and manipulates the audience experience with cunning skill – we may seem to walk alone but an unseen guide leads us on, tugging us one way or the other.

Many familiar Dreamthinkspeak visual and aural motifs are here, and imagery is cross-referenced throughout the show with clever twists: dolls houses and miniature models in ever-more elaborate incarnations; empty beds and abandoned dining tables; mechanical music boxes and waltzing figurines.

Outdoors (trees, snow, ponds, birdsong) elbows its way indoors as an Arcadian ideal, a lost paradise, or a force to be feared; scenes are repeated live and on-screen with Sisyphus-like persistence; and shadowy figures seen only through glass reach out towards us.

Just that would be enough – another Don’t Look Back would be an honourable achievement. But director Tristan Sharps has upped the ante in Before I Sleep – the collaboration with the building and the allusion to its original function throughout the performance is developed to an extraordinary level. Audiences are sworn to secrecy on leaving the show, so the ‘reveals’ shall remain undisclosed – all I can say is that the switches in the show’s aesthetic are unexpected and beautifully realised, and at the heart of the piece is an interactive experience that is one of the cleverest and best-thought-through theatrical ‘games’ that I’ve encountered.

A fantastic show that raises the stakes for site-responsive theatre, and provides an audience experience to cherish long after the exit door slams shut.