The outskirts of Pittsburgh aren’t exactly famous for lonesome prairies and green pastures, but for the would-be cowpokes of “Late, a Cowboy Song,” it’s good enough. This three-character play, an early work by playwright Sarah Ruhl (“Stage Kiss”), is a dreamy exploration of dissatisfaction with conventional suburban life.

Directed by Jen Davis, “Late” is presented by Lux et Umbra, the resident theater company at the Old Marquer Theatre. The show runs Thursday through Jan. 22.

“Late” tells the story of Mary and Crick, played by Rebecca Elizabeth Hollingsworth and Phil Cramer, childhood sweethearts who have grown up and settled down together. When boredom and restlessness start to creep in, the couple drift apart.

Much to Crick’s dismay, Mary starts hanging out with Red, “that girl we went to school with who always wore a money clip instead of carrying a purse.” Red, played by Sam Moltmaker, considers herself a cowboy, and Mary quickly falls for the cowboy lifestyle, spending more and more time with Red and her horses and less time with Crick.

While Ruhl’s best known works are mostly realistic approaches to love and life, “Late” is slightly more impressionistic. The characters gradually lose touch with their work and home life, becoming unattached from the kinds of things that keep most people grounded.

“‘Late’ is about allowing yourself to be honest about who you actually want to be with, regardless of gender, societal, economic or historical norms,” Davis said.

“The magic is sort of rooted in this idea of the open range and boundless opportunity, these things that I think Americans can very deeply and immediately identify with.”

In the script, Mary’s discomfort with her domestic life is exemplified by a small house packed with stuff, a claustrophobic space that seems to be closing in on her. She only feels free when she’s outdoors with Red, communing with nature and animals. (In the play’s stage directions, Ruhl notes that Red’s horse should be “suggested or abstracted,” but adds that she “would not say no to a real horse.”)

The contrast works well on paper, but Davis admits that the scenic demands of the production can be challenging, and the cast and crew, including set and lighting designer Brian Debs, are working hard to get it right.

“You have to have things,” Davis said. “In a show like ‘Late’, just the pure amount of stuff that exists in that moment is really important, so you have to be aware of a lot of moving parts, motion through space, how to bring actors on and off stage.”

Davis has plenty of experience navigating difficult spaces, particularly in her role as artistic director of NOspace, a local theater company that does ensemble-devised work in nontraditional theater venues. In addition to her work with NOspace, she frequently collaborates with other companies around town, most recently directing Southern Rep’s annual production of “A Christmas Carol.”

“Late” is Davis’ first collaboration with Lux et Umbra, now in their second season at the Old Marquer Theatre. The company’s last production, “Faustus,” was well-received, and Davis hopes to build on that momentum.

“It’s always something to be celebrated when a new company takes root, and it’s very exciting when a new company has their own space, especially in a town where most theater companies do not have space,” Davis said. “It’s an exciting time; it’s an exciting company, and I hope ‘Late’ continues on with that tradition.”