WHEN murder calls - hang up.

That's the tagline for the theatre version of Frederick Knott's intense and darkly gripping thriller, Dial M For Murder, famously filmed by Alfred Hitchcock.

For those who've forgotten the plot, it tells the tale of Tony Wendice, who is convinced his wife is having an affair. Now, Tony isn't at all pleased to discover this, and he decides that it's time to take drastic action.

But how to get rid of her? As the play unfolds, we watch mesmerised at Tony's precision in planning what must surely be the perfect murder - until it falters in the most unexpected way.

"Frederik Knott's script is banal, but the plot is outstanding," says Barrhead-born actor Philip Cairns who plays Max Halliday, the wife's lover.

"And the actors give so much to the characters, which makes for a fascinating play."

Taking on the role made famous by Grace Kelly is Kelly Hotten, as Sheila Wendice.

Philip reveals he and Kelly go back a long way.

"This is actually the fourth time I've worked with Kelly," he offers.

"We've done plays such as Edward 2nd, Macbeth and the Duchess of Malfi.

"Its really weird, but when the casting director saw us in the Duchess a couple of years before he recalled we'd had some chemistry togegther.

"And when we realised we were going up for the auditions for Dial M we decided to practise together.

"That got us to the recall stages and we managed to land the parts. Having been pals for ten years, it was great to be working together again."

But now he and Kelly are playing lovers. Does that seem a bit stange?

"Yes, it's odd to be kissing and stuff, but its nice to know you know someone when you go into a play. We've never played lovers before but we're actors, so you know how to connect."

Philip is one of Scotland's most in-demand stage actors. But he didn't grow up with a burning desire to enter the acting world.

A shy kid he was sent along to PACE Theatre school in Paisley, which has helped the careers of current success stories James McArdle, Kevin Guthrie, Mark Rowley, James McAvoy, David Sneddon and Paulo Nutini.

"PACE was better than going off to drama school," he says of the experience. And it was great for shy kids."

Philip went on to train at the Drama Centre in London. But initially, finding acting work was tough.

"It's a lifestyle as well as a job," he says of his career. "I've done so many different jobs in my time. I've done catering, construction, I've worked in London Underground in tunnels. I've done promotional stuff, gardening...

"I've even been an estate agent.

"But this is part of the career. I think you should be malleable as an actor and learn from the experiences."

"In terms of acting however, I will work everywhere."

Now the 29 year-old lives in London, but would move anywhere for the work.

"I've been lucky to do some really nice stuff," he says, smiling.

"And the job I'm doing right now is great."

l Dial M For Murder, Theatre Royal, until Saturday.