A play about cancer, a play about unbelievable fortitude, a play about unique family bonds — none of these in itself is rare. What is exceptional, and on full display in Detroit Repertory Theatre’s Looking for the Pony, is a production whose every component works harmoniously in service of a singular, remarkable vision.

The play’s premise is laid bare in its unusual title: sisters Lauren (Lisa Lauren Smith) and Oisie (Yana Levovna) are the kind of people who, given a mountain of horse crap, see nothing but equine promise, and they’re ever-ready to get their hands dirty in search of the prize. Here, the excrement of the fable takes the form of Lauren’s breast cancer, which emerges abruptly and is fought aggressively, with surprising mirth and no shortage of loving support. Yet it’s a credit to this show, and to director Charlotte Leisinger, that cancer hardly feels like the sole fact of the play; rather, it’s an unfortunate but reliable way of marking the passage of time in their already-full lives, be it Oisie’s graduate writing program across the country or Lauren’s full-time social work, passionate fundraising, and role as Supermom. Even when energies flag or the outlook is dire, these women have vigor and pluck to spare, and the tender, cherished relationship they share provides reason enough to keep fighting.

Playwright Andrea Lepico cycles quickly through the life events of Lauren and Oisie; the confident clip of the narrative makes room for expository flashback scenes that explain how the two came to be fast friends, then stepsisters, and finally as dear to each other as any blood sibling. The tightly woven storytelling format unfolds on a mostly bare set (by designer Harry Wetzel) grounded by a distinctive backdrop, and lighting by Thomas Schraeder admirably helps the transitions that seem to flow by the sentence, marked only by shifting, precisely blocked stage pictures. The costumes (designed by Judy Dery) are similar in form but distinguished by color, providing a blank slate for supporting performers Hank Bennett and Lulu Dahl to play every other inhabitant of this world, from doctors to assistants to professors to fellow patients. Dahl and Bennett use humorous accents and affectations to present the bevy of influences orbiting the inner circle of Lauren and Oisie, and their multiplicity is particularly impressive in a production in which the actors rarely, if ever, leave the stage.

The prevailing fairytale feel (complemented by sound designer Burr Huntington’s music-box melodies) adds the relief of distance between the audience and what’s happening before them; it’s gratifying to see this indomitable take on a story that, in another light, would have been unbearable. But the reality of these sisters lies in their ability to find opportunity everywhere they look, and in this respect, the spirited production rests comfortably on the shoulders of Smith and Levovna. The two understand each other so well that their interactions have a shorthand quality as exclusive as a secret twin language; initially, it’s a challenge to keep up, but their cadence relaxes over the play’s two short acts until nothing but adoration remains. Their closeness is well met in this lead duo: although the play initially seems to be about Lauren, and Smith hints at a deeper reason for her character’s superhuman valor, eventually it must be about Oisie, and Levovna perseveres with sunny determination that feels as natural as breathing. Ultimately, Looking for the Pony isn’t about cancer; as Oisie herself says, this is a play about two sisters with a precious worldview, and the Rep has honored this perspective with a show as thoroughly engaging as it is thoroughly crafted.