David Elms brings a lot of imagination to bear on his first Edinburgh Fringe show in nine years – but uses absolutely none of it on the title.

But it does what it says on the tin. Starting from a single audience suggestion of an item – a water bottle tonight – the comedian gradually builds up a mental picture of a room occupying the space on stage. 

Or rather the audience do, every step of the way. What’s that water bottle made of? What’s its capacity? Is there anything in it? Where shall we put it? And slowly he fills the imaginary space, building up a very detailed picture in our minds’ eye, layer by layer

This is a hugely collaborative process. Every one of us has contributed something to this place, whether it’s a particular type of door handle or the stonking great bird bath placed in the middle of the room.

Occasionally, by saying the first thing that comes into their head the audience can be very funny in their own right – though there’s absolutely zero expectation to be so. In fact, when one man suggested ‘porn’ for what was on a laptop, quite far into this elegant process, you could almost hear a collective sigh of disapproval that he’d gone so directly for the laugh.

Contrast that with the wit of the exchange. ‘What kind of jacket is it?’ ‘A workman’s jacket’ ‘What kind of work? ‘Graphic design.’ 

The conversation and the way the room is built up is so organic. Elms keeps recapping what we have created in the soft, muted tones of a great therapist, cementing it in our imaginations.

This endeavour might not sound like much in stark black and white, especially given its leisurely pace, but it’s surprising how committed everyone becomes to the fictional room under construction. The charmingly understated Elms  – often seen as Mr Swallow’s deadpan sidekick – injects wit and warmth into his interactions, though he was always keen to stress that being funny was never the prime directive.

As the room nears completion, there’s a growing expectation Elms will use it in some way. And not to disappoint he ends with an extended mime utilising every item we have put in this place, often to very funny effect, or sometimes combining items to make a story about what manner of man might live in a place like this. It’s an extended callback, of sorts, but an exquisite one and we are so invested by this point, it’s gripping.

This is surely one of the most original and artistic comedy shows on the Fringe, exploring the power of imagination to create  something new out of nothing every day. That Elms adds improvised jokes is the cherry on top of an unexpectedly compelling hour.