A beekeeper and an academic meet at a barbecue. That’s what happens in the opening scene of Nick Payne’s brazenly unconventional play Constellations, and it’s the only certainty he provides, the only concrete plot point we can latch onto. The rest of this time-bending experiment is comprised of probabilities to explore, options to navigate, theater games to play. They continue chatting, and they don’t. They marry, and they don’t. Infidelities are committed, and they’re not. Nothing happens, and everything happens. This is quantum theatre, and it’s unlike any play you’re likely to have ever seen.

Never one to shy away from challenging material, GableStage artistic director Joseph Adler has selected this unorthodox two-hander as the opening show of his 2015-2016 season, and the result is mind-blowing, niche-y stuff that will play best with theoretical physicists and theater geeks. If you fall into both of these camps, Constellations is as close to nirvana as you’re likely to experience onstage, at least until somebody writes Schrodinger’s Cat: The Musical.

The show only runs about 70 slippery minutes, but its rich emotional aftertaste belies its brevity. It stars Katherine Amadeo as the academic, a Cambridge professor of astronomy named Marianne, and her offstage husband Antonio Amadeo as Roland, the beekeeper. Judging by the accents—which, it must be said, Katherine maintains better than Antonio—it’s set in the U.K., though GableStage’s program wittily lists the “Setting” as “The Multiverse.” We get no specificity from Lyle Baskin’s appropriately abstract scenic design, a series of luminescent benches assembled below a cluster of cloudlike balloons, in front of a wall of stars that recede or brighten depending on the moment.

In their first few exchanges, and many thereafter, the Amadeos are like skilled violinists playing Payne’s words as variations on a theme. In the opening seconds of the play, Marianne approaches Roland with a peculiar pickup line, in full-on Manic Pixie Dreamgirl mode, but he doesn’t bite: He’s married. Thus ends one reality; the lights dim, a snippet of piano music plays, and the Amadeos reconvene at another bench. Marianne offers the same pickup line, and this time Roland chats a bit longer before revealing that he’s already taken. And so on, and until she picks the right door, as it were—discovering the permutation in which the reticent Roland is finally single and willing.

This is how Constellations progresses, in fits and starts, with some possibilities looping forward from the same baseline conversation so many times that audience members will become as familiar with the script as the actors are. This is how life events, from marriages forged and broken to terminal illnesses, proceed, in all their myriad options, barely allowing us time to process one reality before plunging us into a diametrically opposed one. Sometimes there’s even a glitch in the matrix, where we get a taste of a potential future or a reminder of a possible past before bringing us back to the “present,” whatever that is.

This might sound like a lot of work to sit through, but the reason Constellations isn’t as dense as a Michio Kaku thesis is because Payne spells out his intentions with cosmological double entendres, such as Marianne’s retort that “There’s no linear explanation, I’m afraid.” But this Constellations is also such a joy to watch because the two actors treat the source material like the fertile theatrical playground it is.

Putting aside, if you can, its string-theoretical mind-fucks, Constellations is above all a heady meta-study in the art of performance—a revelatory overview of the choices actors and directors make to elicit desired responses. In one version of a painful scene in which Marianne reveals an affair she’s been having with a colleague, Katherine Amadeo delivers the news with guilt; in another, defiance, but with a sensitivity for Roland’s feelings; in another, outright contempt, which suggests her relationship to Roland has already been skidding toward its end.

Antonio pulls off a similar spectrum of emotionality in his responses, and his zenith arrives a few scenes later, in a series of marriage proposals that runs a gamut from bumbling to monotonous to confident. In these alternatives, featuring the exact same words but performed with marked differences in intonation and implication, director Joseph Adler shows us how the sausage is made. And instead of choosing one option, the actors have the rare, liberating permission to explore them all.

Antonio and Katherine, who never leave the stage for the play’s entirety, rise and frequently exceed this central challenge of playing subtle variations on the same fundamental characters. Often, this means transitioning from light comedy to tear-stained tragedy in the space of a brief sound cue, and both transcend these jolting reality lapses. They even learned sign language for one reality, and each hand gesture is deeply felt.

As for the “point” of the play, it’s entirely up to each spectator. It probably goes without saying that not everybody will love this play or this production, which not only colors outside narrative lines—it erases lines altogether. But it’s the most wily, beguiling, life-affirming piece of theater GableStage has produced in years. It goes by in a blip but leaves you with a stimulated brain and a heavy, possibly aching heart.

Best of all? It’ll make you look up at the stars again.

Constellations
Through December 20, at GableStage, 1200 Anastasia Ave., Coral Gables; $47-$60; 305-445-1119, gablestage.org