There’s an updated, blockbuster version of Alice in Wonderland on its way to Broadway, but this charming, unassuming period piece for two actors and a pianist may steal some of its thunder.

The book and lyrics are by Gyles Brandreth, who seems to be everywhere this festival, with music by Susannah Pearse, who’s totally invisible.

She must have gone down the rabbit hole; let’s hope it wasn’t a plug hole. Anyway, Brandreth and Pearse have devised a poignant encounter between Charles Dodgson (aka Lewis Carroll) in his Oxford rooms with Isa Bowman, the actress who first played Alice Liddell on stage, and who now wants to move on.

It’s a true story, and it’s beautifully played in Iqbal Khan’s well-organised production by Michael Maloney as Charles and Flora Spencer-Longhurst as Isa, reviving her performance as Alice one last time. Nice songs, too, some of them set to Carroll’s own imperishably nonsensical lyrics.  Will you, won’t you, join the dance?