Unlike little Kellyanne in the story of Pobby and Dingan, Rob Evans didn’t have imaginary friends when he was a child.

He did have friends – he vividly recalls racketing around with other lads in his home town of Newcastle.

“Looking back, we did seem to live in our own world,” he says. But whatever make-believe was in play, the rough and tumble of the games was definitely real – there were the cuts and bruises to prove it.

Evans also had a far-reaching imagination, and whatever else was left behind in the process of growing up, that has stayed with him. He now has an impressive roster of plays to his credit,

some for adults and others for children – all proving a flair for storytelling enlivened by an engaging spark of magic realism.

His latest venture is Pobby and Dingan. Created for the Catherine Wheels Theatre Company and aimed at ages eight and older, it’s based on a short story by Australian writer Ben Rice.

Evans sketches in some background: “Gill (Robertson, artistic director of Catherine Wheels) had read Ben’s story and been completely blown away by it. I didn’t know it at all. But once I picked it up, I was completely hooked, I suppose, because of the journey it takes us on. I could, absolutely, imagine youngsters getting really caught up in what happens to the 12-year old-boy, Ashmol, because it’s an adventure – he does go off into these dark and scary underground places, looking for these missing imaginary friends of his little sister’s.

“But it’s more than that. It’s about families. It’s about believing in things – a future, maybe – that no-one else can see or touch. And getting other people to believe with you. Believing, actually, that you can do something to change things.”

But what if, as is the case with Pobby and Dingan, your best efforts don’t save the day? Ashmol heads off into hazardous mineworks in search of something he can’t see, only because his little sister has promised to get better if he does. It’s a promise that isn’t hers to keep.

Evans laughs and sighs almost in the same breath. “It does have a very dark side to it, and does deal with death – which is not an easy thing to think about, whatever age you are.”

Actually, he’s been here before. The Night Before Christmas – his 2009 December hit at Stirling’s MacRobert Centre – was a gorgeously whimsical piece for thee-to-five-year-olds who were all agog when a lost elf turned up in a lonely

woman’s bedsit and encouraged her into having enviable fun with him. Almost too late, she understands that if he doesn’t rejoin Santa before the end of Christmas Eve ... well, the love­able elf will die.

Evans’s gut instinct then, as now, was not to dodge away from an outcome where a happy ending isn’t guaranteed. The elf made it, in a lovely sequence of projected graphics.

“I think theatre can open up those challenging situations, leave us wondering about how we’d behave – maybe thinking about family, friends ... the real ones, rather than the imaginary ones.”

The Catherine Wheels’ production of Pobby and Dingan is at Brunton Theatre, Musselburgh (Feb 25-27), Edinburgh’s Traverse Theatre (March 3-6) then touring.