Sandra Marquez and Ora Jones Photo by Michael Brosilow

Set in a "big old house in Iowa City" (convincingly designed by John Iacovelli), the divorced, shy and insecure houseowner Sharon rents a room to a confident stranger named Robyn from the Bronx. Sharon's looking for some additional income and maybe some company in that big old house, while Robyn says she's looking for a fresh start. When Robyn asks Sharon what she does for a living, she says she's retired—from her marriage. Sharon's husband, we learn, lost interest in her years earlier and retreated to spending time with his hobbies rather than her. She has an adult son, a fashion designer living in Brooklyn whom she communicates with only through phone calls that she initiates. Robyn's background is mysterious and is revealed slowly through the course of the play, but we learn she has an adult daughter living somewhere else as well.

The early scenes of this 90-minute one-act play promise to be a female Odd Couple, gaining deserved laughs from the two women's differences, like Sharon's perceptions of the Bronx and Robyn's exotic practices like veganism and use of "medicinal herbs." Director Phylicia Rashad and her two-person cast of Sandra Marquez as Sharon and Ora Jones as Robyn land these jokes with complete comic professionalism, but things take an unexpected turn after the midwestern busybody within Sharon leads to learn some disturbing things about Robyn's past. The Roommate then moves even more unexpectedly into darker comedy when Sharon, who has now become friendly with Robyn, finds those traits attractive. It begins a dangerous transformation in Sharon.

This edgy premise provides a framework for exploring some issues that, while deserving of examination, could easily have become maudlin. Sharon is alone and adrift in what has apparently been a sheltered life. The script gives little backstory, but it's easy to picture that Sharon married young and remained a housewife and mom in Iowa City (which, as the home of a Big Ten university and the famed Writer's Workshop of which Silverman is an alum, is not so provincial as portrayed here). After years of playing the role of stay-at-home wife and mom, she's adrift now that she's essentially neither. She doesn't even know her adult son well enough to suspect that as a single fashion designer living in New York City and with a lesbian girlfriend he might be gay.

Without spoiling too much, it's safe to say Robyn has suffered from similar circumstances, though she reacted differently. Like Sharon, she's without a husband and lacks a satisfactory relationship with her adult child, but without the presumed support of alimony like Sharon must have from her ex-husband, Robyn has found other ways to survive and define herself. The "invisibility" of middle-aged women like Sharon and Robyn—without husbands, children to care for or successful careers—may have allowed them to get away with the illegal behavior they undertake.

Marquez has a breakout role as Sharon. Without resorting to stereotype, she creates a sheltered, lost and lonely middle-aged woman who yet has enough fire inside to bring in a stranger as a roommate and explore changes, however questionable, in her life. She shows us a dramatic transformation in her character, from self-conscious and meek in the early scenes to some carrying the confidence of Robyn as their relationship grows. She delivers the script's humor as well as she breaks our heart in the final scenes.

Ora Jones has the less flashy role of Robyn, who initially seems quite self-assured and unintimidated by her move to such a foreign—to her—land. At first, she's more of a foil for the humor in Marquez's Sharon, but this masterful actress lets us see Robyn's underlying regrets over the life choices (or maybe the limited choices she had) that have led her to seek a fresh start in this land "where things grow." Her difficulty in giving up old habits is foreshadowed by her inability to quit smoking. Similarly, when Sharon shows an interest in Robyn's past indiscretions, Robyn starts to fall back into old ways. Jones shows us the underlying tension of this development that Robyn would never have anticipated.

Sharon's transformation from mousy housewife to something more dangerous happens so quickly (both in stage time and story time) so as strain credibility. This is mostly a flaw in the script, though there might have been a way Marquez and Rashad could have suggested Sharon was susceptible to such dramatic change. That, along with the unpredictability of the plot (refreshing as that is), makes The Roommate a little unsettling on a first viewing. Even so, it only takes a modest suspension of disbelief to go this entertaining ride, which not only provides an opportunity to see these two brilliant actresses at work, but to experience an unsentimental look at a segment of society that doesn't get nearly enough of our attention.

The Roommate, through August 6, 2018, at Steppenwolf Downstairs Theatre Company, 1650 N Halsted St., Chicago IL. For information or tickets, visit www.steppenwolf.org or call 312-335-1650.