Audiences in London are flocking to new productions of "immersive theatre" - secret, tailored shows in often wacky locations which take audience participation to a new extent. But what is behind this trend and did it originate in the capital?
Everyone is looking around at everyone else. They're wondering what to make of the intimidating, bedraggled man standing in front of us.
We've just been ushered into his space, a stale-smelling shipping container strewn with empty water bottles that he frantically gathers up as we enter, the occasional sounds of crushing and rebounding plastic echoing back.
Now still and silent, his eyes flit nervously to and fro inside his mask, which depicts some hellish version of a human face, bent and tortured in its bizarre features.
The audience is here voluntarily, although you might not know it from the stolen glances darted around the room.
Fear, uncertainty and excitement are the main emotions you feel as you move from container to container, shepherded here and there through hidden entrances by a surreal cast of actors, all wearing their disturbing masks. They never quite connect with the audience, forcing you to question what you should be doing, whether you should be interacting more or less with the performance.
Such is the mysterious appeal of The Boy Who Crawled Out of His Face - one of a string of "immersive theatre" productions that have proved popular in recent months.
Over the river, just next to the Olympic Park, audiences in search of a similar experience could find themselves on a set of Secret Cinema recreating the town square in the 1980s hit film Back to the Future, inviting punters to re-experience one of their favourite films in real life.
While very different in scale and feel, both productions offered an involving surprise fantasy in the realms of so-called "immersive theatre" - a kind of extreme escapism that seems to have taken root in London, with new shows popping up every few weeks.
But is this an isolated trend - the latest outlet for experimental theatre directors working in the capital? Or does it reveal a bigger appetite for escapism encompassing computer games, social media and even playing pretend as zombies?
The diverse strands of immersive theatre "appeal to hedonistic desire", says Dr Adam Alston, lecturer in theatre and performance studies at the University of Surrey.
"It offers something of the fun, entertaining, cool and exhilarating qualities of festivals and clubs," he adds.
Analysis: By Will Gompertz, Arts Editor
Immersive theatre has been around quite a while now - you could argue all the way back to Shakespeare's day and the thrust stage.
The latest fashion is a reaction to the digital age and people's desire for a live, shared experience. Hence the rise in popularity of theatre, festivals and performance art.
The "experiential" scene is over a decade old now - think of all those people lying on their backs in Tate Modern when Olafur Eliasson's Sun was installed in the Turbine Hall.
I'd say London has been something of a centre, with Punchdrunk et al, but I wouldn't discount the contribution that New York, Berlin and Manchester (with its International Festival) have contributed.
For a recent production of Macbeth in east London, the audience stayed 12 hours overnight in a decaying 27-storey tower block, as the play was acted out over three floors. Punters were then invited to sleep in one of the flats before watching the sun rise together on the roof the next morning.
It may not match Michael Sheen's 72-hour performance of The Passion at Port Talbot, but David Shearing, a lecturer in theatre and audience immersion at Leeds University, says the immersive Macbeth gave "a real sense of being part of something".
"You feel like you're on a journey," he said. "We buy into the experience and not just the performance."
He said the parallels between immersive theatre and computer games were clear.
The Drowned Man, a recent London production, Punchdrunk, left audience members unguided, wandering through extravagantly decorated rooms - letting them decide whether to stay put or follow characters as they explored the space.
"The rules and the structures are the same," Dr Shearing says. "You have to go through levels, especially in Punchdrunk, where you have to hunt out clues and explore the world."
Destiny, an internet computer game, is just the latest example. Costing $500m (£312.3m) to develop and promote and drawing in 4.5m people worldwide to help test its pre-release versions, it hopes to have 10m players plugging in on day one.
In today's world, generating an experience is everything, says Dr Alston.
Immersive theatre producers "put audience members centre stage" in an apparently tailored experience, including audiences in the action "to make their 'escapist' experience all the more unique and personal to them".
The trend even reaches into the horror genre, giving people the chance to become one of the undead in a 'zombie bootcamp', or inviting them to be chased around British city streets by zombies on a pre-designated course in 2.8 Hours Later.
Immersive theatre productions can now be seen in New York, Berlin, Rio de Janeiro and other global cities, says Dr Alsoton.
But what role does London play in all this?
According to Mr Shearing, the trend began in the mid-2000s with shows at Battersea Arts Centre and Tate Modern's Turbine Hall.
Ben Power, associate director at the National Theatre, said the capital had been a "really important" incubator for immersive theatre on the world scene.
"Things have grown up in London and Europe that find their way to the US in a mutated form," he says.
This is partly due to the expense of putting up shows in unusual spaces in other global cities. Adam Feldman, theatre critic for Time Out New York, said some innovative productions "require such a huge space that it's hard to find somewhere in New York to hold it".
Back on the jetty reaching out over the River Thames, the production company Shunt claims it measures the success of its bizarre production by how far the medium has been pushed - and not the numbers that pop up in its bank account.
Co-founder Gemma Brockis says: "I think we judge our success by our audience and also our own perception of what we find interesting and how we feel we've challenged ourselves - or surprised people, or surprised ourselves."
The show's first night had to be cancelled because of lightning - perhaps the price of risk-taking on such a scale.
But far from being a Londont trend, immersive theatre seems to have plenty of life left in it, whether you want a new brand of escapism or just a good night out.