Graham Rowat and Kate Baldwin Photo by Emma Rothenberg-Ware

The characters are in England where she is a quantum physicist at Sussex University while he keeps bees. They meet (at a barbecue) and, at some point, she draws comparisons between the theory of relativity and her quantum field. The former speaks of the universe, inclusive of stars, the sun and the moon and the latter more about atoms and molecules. Those worlds, for a layperson, seem juxtaposed. Are they really oppositional or can they exist, in a sense, side by side?

Playwright Payne, moving from the scientific to most personal, affords the two souls on stage situations for a multitude of mini-relationships. Further, there are do-overs, the opportunities to say or play something differently which leads to a more positive result. Constellations is both intellectual and intimate. The allusion to string theory is elusive to many who are not well-versed in physics. The Yin and Yang, the struggle for balance, the effort Marianne and Roland evidence: this is the substance, however, of enduring, significantly moving theater.

Alan Edwards designs set and lighting — the performance space is gently rounded with light bulbs as stars are positioned above. Costumer Laurie Churba chooses a black with white floral dress for Marianne. Kate Baldwin's is redheaded and her skin seems almost translucent during portions of the production. Rowat, a big guy wearing jeans, brings a warm presence while she, sweeping her hair away at times, is initially nervous. Director Edelman moves his players around to avoid stagnation and to allow for breath within each vignette.

The contemplation is about the possibility of very different galaxies existing in parallel fashion and the question of whether people, pushing and pulling, are able to finally bridge differences and forge a life together. Do we mortals have a choice? Are we able to control tempo and circumstance? Is a greater entity, one dictating terms of fate and chance, the ultimate determining factor? Constellations raises these questions are more during its one hour journey. Marianne's illness, addressed late in the play, moves the story toward another dimension.

This play bids these talented actors, each known primarily as a musical performer (A Little Night Music and Bells Are Ringing for BTG the past few summers), interpret a poignant, difficult script — without music and many other characters surrounding them. In addition, British accents are required; all is accomplished with graceful fluidity. There's the import of Payne's dialogue and the multitude of thoughts and feelings each character holds - complexity which deepens as the script concludes.

Baldwin and Rowat, as the play begins, are tentative toward one another; this is accurate. Later, their comfort level (as people who have been married for a number of years) assists them with Marianne and Roland. There isn't any hesitancy and, instead, we are watching people alone on a stage who might be able to searching for vulnerability and possibility. While these individuals are fully clothed, their emotions are raw and in the open. The play is not easily executed or understood. It demands that each actor reach for truth. Baldwin and Rowat, given a work which is written with care and discipline, are fully persuasive. Please consider one hour of sublimely challenging live theater.

Constellations, at the Unicorn Theatre on the grounds of Berkshire Theatre Group in Stockbridge, Massachusetts, continues through August 27th, 2016. For tickets, call (413) 997-4444 or visit www.BerkshireTheatreGroup.org.