Constellations is a love story about the same people in different universes, exploring the themes of free will and friendship.

Written by Nick Payne, who was this week chosen to write the screenplay adaptation to David Nicholls's top 10 bestseller Us, Constellations comes to Richmond Theatre this month.

Joe Armstrong plays Roland, a pretty laid back and relaxed bee-keeper, while scientist Marianne is played by Louise Brealey in this award-winning production.

It has enjoyed sellout runs in the West End, as well as Broadway, and Armstrong believes its unusual themes go some way it explaining its success.

"The play is so unusual because it keeps flitting between different universes and different realities," he says.

"But it is the same two characters throughout, although it is fundamentally still a love story like many others.

"It explores the theme of multiverses and parallel universes, as well as the decisions we make and the decision that we don't make.

"Neither of them realise they are in parallel universes either - it is very easy to get a handle of once you are watching it."

With just two actors on stage for the entirety of the play, Armstrong acknowledges it is an unforgiving environment in which to perform.

He says: "I have done two-handers a few times before and I do enjoy it - there is a trust required and you never leave the stage.

"There is nowhere to hide once you are up there and it is quite a powerful experience."

He plays Roland, who he describes as a "straight forward guy" and more laid back than his scientist girlfriend, Marianne.

And he is undoubtedly excited about being part of such an acclaimed production.

He adds: "The play has been done before successfully and I don't want to get dramatic about it but is really, really excellent writing."

Constellations; Richmond Theatre, Little Green, Richmond; June 23-27, evenings 7.30pm, matinees 2.30pm; tickets £11.90 to £45.40; visit atgtickets.com/richmond for more details.