“You wanted to destroy me!”

“I wanted to honor you!”

The emotional journey that leads to these heated words between Ruth Steiner and Lisa Morrison is the subject of Donald Margulies’ “Collected Stories.” From the onset, the relationship between Ruth (Bobbie Steinbach), a seasoned writer, and Lisa (Liz Hayes), a graduate student studying under her, is portrayed as one that is constantly evolving. It’s hard to say with absolute certainty whose transformation is more profound: Lisa’s transition from awkward, naïve graduate student to accomplished author or Ruth’s transition from a sarcastic, bad-mannered professor to adopted mother who is capable of feeling scorned by her protégée.

Unfortunately these parallel transformations are not equally compelling; Steinbach’s authoritative performance carries the play, and though she could outshine many skilled actors, she is nonetheless held back by her comparatively underwhelming co-star.

“Collected Stories,” which runs until October 30 in the Charles Mosesian Theater at the Arsenal Center for the Arts, spans the years following Lisa’s first appearance in Ruth’s Greenwich Village apartment. The apartment is the only set used throughout the play, and effectively centers the focus on the interactions between Ruth and Lisa. Its consistency and simplicity is a fixture that makes the change in the characters’ dynamics more evident and striking.

With only one set and two characters, the bulk of the play’s success relies on the strength of the actors’ performances. While Hayes is not without considerable talent, it is only halfway through the play that she seems to hit her stride. Her naïveté at the beginning is conspicuously overplayed and delivered without subtlety. The result is a stale performance that stunts the possibility of a fully developed and moving character.

On the other hand, Bobbie Steinbach’s performance not only dwarfs her co-star’s efforts, it also manages to lend credibility to the production and elicit genuine emotion. While Hayes struggles to embody young Lisa, Steinbach captures Ruth Steiner effortlessly. She nails every nuance and creates mannerisms that are in sync with Steiner as a character. A prime example of Steinbach’s breathtaking skill is a monologue in which she describes her life as a young, aspiring writer and meeting the man of her dreams. She recounts the story while staring off into the distance and fiddling absent-mindedly with a blanket, her voice marked by an astounding and genuine nostalgia.

Tyler Kinney’s costumes serve as visual cues for the changes in the characters’ emotional states. A shift in wardrobe from muted, pastel sweaters (complete with a ridiculous side ponytail) to a tomato-red cocktail dress symbolizes Lisa’s metamorphosis. Although Lisa’s styling at the beginning is overstated, the use of costumes as an allegory for personal change is generally an effective ploy. The decision also helps along Ruth’s character: as she succumbs to an unnamed illness, her clothes gradually show her decay.

As might be expected from such a spare set, lighting also plays an important role, though mainly in the finale. Most of the time Ruth’s apartment is completely lit, but the play ends with the spotlight focused on Ruth, sitting alone at her typewriter. The light slowly dims until all that’s left is the outline of her frail figure.

The ambiguous ending seeks to ask one main question: what stories are yours to tell? Who gives a writer the authority to use other people’s stories? These questions of literary ethics purport to be the play’s main thematic focus. But on stage, “Collected Stories” functions best as a simpler tale of Ruth and Lisa’s fictive kinship.

On that level, director Bridget O’Leary manages to work the set, lighting, costumes, and undeniable chemistry between the two actresses into a true human drama. Despite a rocky beginning, the play’s various aspects coalesce to convey a simple yet powerful message about the complexity of human relationships.