We've all had the experience of wondering what would have happened if things had been different at certain points at our lives.

Nick Payne's award-winning play Constellations.draws on theory of the multiverse proposed by some scientists including Stephen Hawking - with many parallel universes existing simultaneously - to consider this notion in the context of a poignant romantic comedy.

It tells and retells the story of two very different people - quantum physicist Marianne (played by Lexi Sekuless) and urban beekeeper Roland (Kristian Jenkins) - who meet at a barbecue, exploring the many possibilities of what might happen over the next five years. Will they get past an awkward hello? Will they be able to become a couple? Will they stay together if they do? And what will happen to them along the way?

Given the number of universes in which the scenario is playing out, the possibilities seem endless, and the play depicts longer or shorter excerpts from as many as it can - sometimes funny, sometimes dramatic, sometimes poignant - as we see the lives of these two people unfold in many ways.

Sekuless saw the play at the Royal Court in London in 2012 during its premiere season - "the home of all new work in the UK when I was there," she says. Payne wrote it when he was 26 and it was a critical and commercial success. It was named best play at the Evening Standard Theatre Awards before going to have productions on Broadway, in 2014, and elsewhere.

She says it's been a feature of the work of European playwrights to present non-realistic, even surreal elements on stage and younger British playwrights such as Payne and Lucy Kirkwood are continuing in this vein while remaining accessible to audiences.

"It's very elegant envelope-pushing type-work."

This will be Sekuless's first time working at the Street Theatre following time spent in Britain studying at London's Central School of Speech and Drama and performing roles such as Lady Anne in Richard III at The Globe. She says she was keen to act in Constellations having seen and admired it and also wanted to work with Caroline Stacey at the Street.

Her character, Marianne, being an academic whose field is quantum physics, is a thinker, interested in big ideas like parallel universes and free will versus determinism but she's also someone who feels deeply about what's happening to her, Sekuless says.

"She's got this depth and intensity about her - she's got a scientific mind and won't put up with superficiality; she would prefer to be with people who think like her."

All of which might make it interesting that she would even entertain the possibility of a relationship with the easygoing Roland, an urban beekeeper, a man who works with his hands more than his head. Is it simply a case of opposites attracting? What else is there to sustain a relationship?

Jenkins found the ideas behind the play fascinating and the way they played out fun to explore and says the characters in each universe "were the same in terms of DNA" even if their situations and even their personalities sometimes varied, sometimes markedly, depending on the circumstances of the particular scenario they were playing out and the nature of their relationship.

This is the British-born Jenkins' first performance at The Street Theatre. He completed an arts degree and works at a bank in Brussels while taking part in amateur theatre before deciding to pursue acting more seriously. He completed a one-year masters degree at the Drama Centre in London and went on to work in Britain, Europe and the US, one highlight being the title role in Macbeth for Welsh company Sherman Theatre.

He moved to Canberra after falling in love with an Australian woman and works part-time at a think tank while acting when he can - he will be seen on the upcoming ABC TV show The Easybeats.

The actors - and lighting designer Owen Horton and sound designer Kyle Sheedy - are having their first professional engagements at the Street Theatre. However, set and costume designer Imogen Keen has worked on more than 20 shows there. She says Constellations "has a lot of binaries to it - it's a romance but it has a bit of a dark side ... the challenge is to support the ideas".

One of its visual themes, she says, is the idea of the multiverse, which can be be represented in either a very complex or very simplified fashion. Collaborating with Stacey, she's gone for the latter approach - "a simple clear, response" - so the focus is on the two performers.

The costumes, too, have been kept simple, and there's a natural element to the design colour palette - honey, blue, green - with obvious resonances of nature and sky and Roland's work, in keeping with the themes of the play.

"It's not a spectacle piece, it's about the relationship between these two people. It's all about enabling the audience to connect the sense of variety of possibilities and help them to think."