WHAT value do workers have, in a world of zero hours contracts and near invisibility?

Where is the dignity in honest toil when companies are looking to reduce not only rates of pay but basic levels of self-respect?

That’s the theme of this week’s Oran Mor play, Dirt Under The Carpet.

Rona Munro’s play features Muriel and Lorraine, two night-time office cleaners in the Aberdeen oil industry. But they’re not just ordinary cleaners, these two ladies are premiere league cleaning ladies, the best.

The take immense pride in their work, but they don’t take it all so seriously they can’t have a bit of fun while they work.

As the pair polish and sweep and put a shine on everything they touch, they slip into role play.

Muriel, in her sixties, and Lorraine, in her twenties, like to imagine the lives of the workers they never meet.

“They give them characters, they give them a backstory,” says Joyce Falconer who stars as Muriel.

“They use this as a means of getting through their day, stirring up their imaginations a little.”

But however hard they work, the pair can never get things clean enough to satisfy the tyrannical boss, Mr B.

They don’t see Mr B but they are constantly threatened by post it notes. Which means their working lives are threatened.

Then one morning they find the worst mess of all, Mr B’s corpse. Who killed him, and why?

“These women are diligent, they take great pride in their work,” says Joyce. “And we learn that Muriel has been doing the job for thirty five years.

“But the new boss has arrived and she’s under pressure.

“The oil industry is in the grip of a recession and she feels insecure as warnings for inefficiency accumulate.”

We learn more of the cleaning women. Muriel loves her home town but she’s lonely. Her children have flown the nest for far-flung destinations that she can rarely afford to visit.

Meanwhile, Lorraine isn’t quite as she would seem. She’s a wannabe singer/songwriter and we learn she has something of a dark past.

Lorraine’s plans have gone awry after a long spell in prison for assaulting the man who stole her heart, but also her intellectual property, claiming that Lorraine’s songs were his own.

But are either of these women capable of murder?

“It’s a murder mystery,” says Joyce of the storyline, smiling. “The play has its black comedic moments but essentially it’s a whodunit.

“We are gripped wanting to know who has killed Mr B. But along the way, we certainly get the feeling he deserved it.”

Joyce knows the world she is attempting to recreate at Oran Mor this week.

“I worked as a tea lady in the oil industry,” she says. “It’s all very familiar to me. And although the play was written in 2007, the industry is going through another recession right now.

“It makes it all so relevant. And this is a play about showing lack of respect for workers. Sadly, that situation remains the same.”

Joyce Falconer brings an immense experience to her role. Over the years the actress, fresh from playing Ma Broon in the touring musical comedy, has appeared in a great range of Oran Mor parts.

She has played an ex-factor contestant, a Russian stationmaster, a fisherman’ wife, the Brazilian Fanny Cha Cha – and a signalbox.

“I love the challenge of Oran Mor,” she says.

Co-star Karen Fishwick is one of the fast-rising stars of Scottish theatre. Karen has toured with his musical Our Ladies of Perpetual Succour and more recently starred at the Citizen’s Theatre in Hansel and Gretel.

Rona Munro has had immense success recently with the James Plays and has written several times for Oran Mor.

All this suggests theatre success. But what of Mr B? Is there an actor out there who has to spend fifty minutes on the floor, trying not to reveal a breath?

“No, that doesn’t happen,” says Joyce, grinning.

“We don’t actually see the corpse. It’s all concealed off stage. But the corpse isn’t too important.

“What is important is how these women have had their lives affected. All they want to do is clean, and dream a little.”

Joyce, who has been touring with her one-woman show, once worked as a cleaner, for a firm of accountants.

“Thankfully, they were quite a nice company to work for,” she says of her time having left drama college.

“But that’s not always the case with cleaners. It can be a thankless task.”

• Dirt Under The Carpet, Oran Mor, until Saturday.