Horizon’s ‘Grand Concourse’ loses its momentum

Through April 26. 8 p.m. Wednesdays-Fridays; 8:30 p.m. Saturdays; 5 p.m. Sundays; 3 p.m. Saturdays (April 11 and 18 only). $20-$30. Horizon Theatre, 1083 Austin Ave. (in Little Five Points), Atlanta. 404-584-7450, www.horizontheatre.com.

Bottom line: A test of faith in more ways than one.

Heidi Schreck’s dramatic comedy “Grand Concourse” takes place in a church soup kitchen, principally involving the touchy relationship that develops between Shelley, the middle-aged nun who runs it, and Emma, a flaky college dropout who enlists as a volunteer.

We know from the opening scene — the first of several “prayers” she recites throughout the play — that Shelley is already grappling with issues of wavering religious conviction and personal compassion. And we know, once Emma shows up with her rainbow-colored hair and materialistic fashion sense, that she will put those conflicts to a further test.

Initially espousing the importance of “maintaining boundaries” — not only with her staff, but also with the homeless “guests” they serve — Shelley gradually lets down her guard and warms up to the girl, after Emma reveals that she’s undergoing chemotherapy treatments for leukemia, professing her need for “human company” and a desire to “give back to others.”

So far, so fair in co-artistic director Jeff Adler’s Horizon Theatre production. Regrettably, around the halfway mark, “Grand Concourse” takes a drastic turn for the worse from which it never recovers, with a couple of plot twists that are simply far-fetched, if not somewhat infuriating.

To divulge anything more specific, alas, would be unprofessional. (It sure is tempting, though, to call Schreck on what’s basically her own bluff.) Let’s leave it at this: Just as events force Shelley to redefine her opinions about Emma’s character, they challenge the audience to remain invested in Schreck’s play.

Adler casts Maria Rodriguez-Sager as Shelley. Whatever her real age, the actress has been most persuasive in a couple of recent younger roles (in Horizon’s “The Waffle Palace” and Theatrical Outfit’s “My Children! My Africa!”). It isn’t that she lacks talent or presence, but here, playing a woman who’s pushing 40, her hardened world-weariness tends to feel affected instead of truly lived.

For her part, more experienced actresses than Alexandra Ficken might be hard-pressed to bring any greater emotional legitimacy to Emma. (Bless her heart, she was coincidentally burdened earlier this season with a similarly problematic character in “FML…” at 7 Stages.)

Neither of them is fully capable of validating or overcoming the implausible and melodramatic shifts in the plot. Curiously, in supporting roles, their male co-stars render the better performances.

Allan Edwards portrays one of the soup kitchen’s regulars, a heavily medicated misfit prone to telling bad jokes in one breath, and then spouting profound observations about life in the other. Even better is Evan Cleaver as a hunky Hispanic co-worker and an unwitting object of Emma’s affection.

Another undeniable asset of the show: Sisters and scenic designers extraordinaire Moriah and Isabel Curley-Clay have outdone themselves — yet again. If you don’t believe much else about “Grand Concourse,” at least you can believe that.