A strikingly impressive feat of memory, world-building and forging of communal purpose, David Elms Describes A Room finds the genial improviser moving towards a single, delightfully ephemeral scene built on nothing more than offerings from his audience. Soliciting suggestions for household objects from people one by one, with a sense that everybody will get a turn (but a single turn only), Elms creates a room out of thin air, periodically summarising the contents. Offering only minimal direction, a few follow-up questions here, a quizzical eyebrow raise and entreaty for further clarification there, he nevertheless stresses that there is no pressure for anyone to try to be funny. Or, indeed, to take the enterprise too seriously. Simply say the first thing that comes into your head and believe in his assurances that the show will write itself.

And certainly, it’s compelling to see the manner in which total strangers react to and construct upon others’ imaginations, the workings of the brain at times inscrutable and unfathomable, but in others voicing what was surely in everyone’s head. Phil Wang has been quoted likening Elms’ method to creating a mind palace, à la Sherlock Holmes. And there’s certainly a sense of a fictional detective about him as he slowly circles the space, summarises once again, then delivers the theatrical retelling of precisely what went down in the room this evening. Frivolous but profoundly human storytelling.

David Elms Describes A Room, Pleasance Courtyard, until 24 August, 9.35pm; main picture: DEDAR.