The studio behind the Festival Theatre is, in my opinion, a hidden theatrical gem in Edinburgh. Whatever gets put on there is invariably interesting, invariably unusual, and always worth seeing. And this time, it’s struck again.

Lung Ha Theatre Company designs accessible shows, performed by and for people with learning disabilities. Their latest, Thingummy BOB, was written by Linda McLean (who also wrote Glory on Earth) and thoughtfully directed by Maria Olle, and is both touching and charming.

Bob (John Edgar) is an elderly, disabled man living in a care home, and he’s lost something. He’s not sure what it is, but he’ll know it when he sees it. His friends, Gemma and Cap, played with great humour by Emma McCaffrey and Mark Howie, decide to help him look for it. Meanwhile, they’re watched by a security camera, narrated with dry wit by Gavin Yule. Kenneth Ainslie provides the rest of the characters: Bob’s nurse, a friendly neighbour, and even an invisible dog. It’s all done with a knowing nod to the audience – Thingummy BOB is notably without fourth wall, to great effect. I’ve rarely seen a cast get an audience on side more quickly.

Another strength of Thingummy BOB is Philip Pinsky’s sound design. The Beatles and the theme from The Great Escape turn up at various points, adding humour and acting as touchstones for the cast to riff off. Designer Karen Tennent’s staging is on multiple levels, with wheelchair ramps linking them together – both Edgar and Yule perform in their wheelchairs. For all that it’s unusual to see in theatre, the wheelchair-accessible set is both clearly well-considered, and also seems, well, obvious rather than remarkable. The involvement of a chair-based bait and switch (I shan’t spoil it for you, but it’s very funny) is one of the high points of the show – and it’s a shame you’d be unlikely to come across a comparable stunt elsewhere.

At the heart of Thingummy BOB is a story about the day-to-day life of a man with dementia. For all that dementia involves some inevitable sadness, Thingummy BOB is not a pity-fest; it’s fundamentally warm, and kind, and good natured. It’s impossible to leave the theatre without a bit of that glow rubbing off.

For more on the King’s and Festival Theatre’s Programme click here.