The Room in the Elephant. Originally seen at Oran Mor in Glasgow in a co-production with Bristol's Tobacco Factory, Wainwright's play looks at what happened when iconic street artist Banksy sprayed the words 'This looks like an elephant' on the side of a water tank in Los Angeles.
For the previous seven years, the tank had been the makeshift home of Tachowa Covington, who had furnished it to become something of a bespoke miniature des-res. Now Banksy had given it the tag of celebrity, however, the tank was designated a work of art, removed, and sold off to the highest bidder.
"Banksy Brings Misery To Homeless Man" one newspaper headline announced when Wainwright's look at art, commerce and real life first appeared.
Things got even stranger during the play's Edinburgh Festival Fringe run, when film-maker Hal Samples, who was making a film about Covington, flew his subject over from America to see the play.
This experience became integral to Something From Nothing, the resultant film which is being screened at the Traverse after each performance of the play.
"I had just approached Hal to get a photograph of the tank for the show," says Callander, who this week brings her production to Edinburgh's Traverse Theatre, where she was recently appointed Associate Director, "and we've ended up becoming the conclusion of his documentary, and the play now feels like a piece that's about the morality of something."
Callander's production of Banksy: The Room in the Elephant is her highest profile outing at the theatre she now calls home, since she first co-directed the now regular Theatre Uncut seasons of work.
These hot-off-the-press short plays reacted to events going on in the world, and a new season will appear in Edinburgh in August. Such socially-aware work is a far cry from Callander's original training as an actor after spending her youth doing shows with a light opera club in Bristol so she could hang out with her best mate.
"I wonder if she'd have been in a football club or something whether I'd done that," Callander muses. "I had a really good time as an actor," she says, "but I always felt something wasn't quite right. I felt I wanted to explore theatre more, and was always thinking of the bigger picture, so was probably one of those really annoying actors, always chipping in.
"My dad's a philosopher, and I was brought up on big ideas and questioning things, and it took a while to realise as an actor that I wasn't quite in the right place."
Callander ended up working in Poland with experimental theatre company, Gardzienice, on a production of Iphigenia at Aulis.
"We were working in the forest," says Callander, "and doing that, away from my usual surroundings, I felt that it might have been directing that I wanted to do."
Callander ended up assisting American wunderkind Daniel Kramer at the TR Warszawa company in Warsaw. She then worked with Vicky Featherstone and John Tiffany at the National Theatre of Scotland prior to their departure to the Royal Court. For A Play, A Pie and A Pint, as well as Banksy: The Room in the Elephant, Callander also directed Dalgety by David Greig and Supply by Cathy Forde, while this season she worked on Queen of Lucky People, by Iain Heggie.
"I feel like a kid in a sweet shop," Callander says of her new role, "but coming into a theatre that has produced some of the best plays in the English language, I also feel a sense of responsibility. I'm completely devoted to new writing, and writing that says something about the world we live in."
While Banksy: The Room in the Elephant is clearly an example of this, for Tachowa Covington, things haven't changed much.
Callander says: "Our production hasn't particularly helped him. He now lives in a tent in a forest, and no-one in his community believes this happened. They don't believe there's a play, and they don't believe he came to Edinburgh, so that's our next mission, to do the play on a beach close to where he lives."
All of which begs the question of what the reclusive Banksy makes of all this.
"We contacted him a long time ago," says Callander, "but never heard anything. We didn't want to cash in on his name, but after all this happened, I know Banksy gave quite a lot of money to Tachowa to make sure he can survive. Banksy's done good. He's done his duty. Maybe he's even been to see the show?"
Banksy: The Room in the Elephant, is at Traverse Theatre, Edinburgh, tonight and tomorrow. Each performance will be followed by a screening of Hal Semple's short film, Something From Nothing.