"When most people think of Treasure Island, they think it's either a musical or a pantomime, and this isn't," says Gavin Robertson, who stars as pirate captain Long John Silver in the Birmingham Stage Company's latest adaptation.

"This has gone right back to Robert Louis Stevenson's book. There are no jolly pirates doing lots of little hornpipes in this version. It's all quite nasty and vicious, which is nice in this PC age.

"It's definitely aimed at children, of course. All they've done is stay true to the spirit of the book rather than Disney-fying it."

Robertson, who grew up in Horsham and now lives in Eastbourne, made a career creating his own work for 20 years, most famously with his Thunderbirds spoof, which played in the West End on six separate occasions. He only began to gravitate towards children's theatre at the turn of the century.

"I have a son and when he was about nine, I was taking him to the theatre and about 97 per cent of what I took him to was just rubbish," he explains. "It was condescending, three actors on a papier mache stage, stripy jumpers - it was like play-school. And I thought, I can do better than this. I'll make something.' "So I was driven like an angry parent to stamp my foot and create my own piece of work for my son. How arrogant is that?"

The result was a piece called Message In A Bottle, which saw Robertson christened "the Tim Burton of children's theatre" by the BBC. He says he has "just fallen into being an actor" since a producer asked him to be in Twelve Angry Men, alongside Bill Bailey and a host of other stand-up comedians. That 2003 show was a success and Robertson was then asked to appear in the company's follow-up production, One Flew Over The Cuckoo's Nest, starring Christian Slater.

"There was no audition. They just rang me and asked me if I wanted to be in it. It was an actor's dream, really," he says. "You go, Yes, OK. Thanks very much. Who did you say? Christian Slater? How long? West End? All right then, why not? I think I'm free.' "Christian is a great guy, a very nice bloke. None of us knew what to expect. I mean, he's a Hollywood film star. You're not quite sure what's going to happen in the rehearsal room. Is he going to talk to you? Is he going to turn up with three bodyguards? But the first day we did the rehearsals and went to the pub."

While he has thoroughly enjoyed this unplanned diversion, Robertson feels he may soon return to the physical comedy which made his name.

"I have a lot of fun with Long John Silver, I have to say. It's great to limp around the stage and be particularly nasty to almost everybody. But you probably can't be silly in such an overt way," he laughs. "I've been quite serious now for six or seven years and I think a return to stupidity is on the cards."

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