By Hannah Moscovitch. Directed by Ross Manson. Copresented by Volcano Theatre and the Cultch. At the Cultch Historic Theatre on Wednesday, January 8. Continues until January 19

Infinity is one of the most fascinating and near-flawless productions the Cultch has ever presented. It’s challenging and smart, raunchy and complicated, and heartbreaking in ways the audience was not prepared for—at least based on the audible weeping coming from all corners of the house on opening night.

We meet Sarah Jean (Emily Jane King) returning home from a funeral, obsessing about her terrible history with love. Then the scene shifts and we witness the first meeting between theoretical physicist Elliot (Jonathon Young) and violinist-composer Carmen (Amy Rutherford). He studies time, a subject that he can tell preoccupies her, as a musician. Therefore, he says, they belong together. But she just broke up with her fiance two days earlier. “I can offer you 15-20 minutes of sex followed by 40-45 minutes of crying,” Carmen says by way of rejection, unwittingly confirming Elliot’s theory about their shared obsession. They kiss and maybe he’s right, but it’s definitely not simple.

As the scenes alternate, we learn more about Sarah Jean’s failed relationships (“there was a lot of chalk dust in his pubic hair”) and we see how fraught Elliot and Carmen’s partnership is from the beginning. His work consumes him while Carmen is left raising their daughter largely on her own. Additionally, major mother issues plague both characters, though this slightly misogynistic trope always leaves me asking: where were the dads? Neither Elliot’s nor Carmen’s fathers are mentioned. Despite that lingering question, Infinity is beautifully written. Playwright Hannah Moscovitch’s way with dialogue is masterful. Carmen and Elliot hurl knives at each other and plant flowers in their wounds only to unearth it all and do it over and over again. Both the frustration and tenderness are exquisitely, painfully real.

Young and Rutherford have a wonderful dynamic—he’s all oblivious, awkward charm and she’s deadpan and desperately lonely. As Sarah Jean, King does an incredible job delivering some of the play’s funniest lines. Throughout Infinity, violinist Andréa Tyniec is also on-stage in the background. She brings composer and music director Njo Kong Kie’s remarkable score to life, ratcheting up the tension and infusing more emotion into already volatile moments. Even Infinity’s sole choreographed interlude—which might have been a jarring interruption in a lesser play—works.

This is all a credit to Moscovitch’s collaborative process, not only with choreographer Kate Alton, but also with Njo, director Ross Manson, and consulting physicist Lee Smolin. Both Moscovitch's and Manson’s program notes talk at length about how each person’s contributions informed Infinity’s creation, and you can see it coalesce on-stage.

Infinity is its own universe, and it’s a stunning one at that.