For me, it was the wooden spoon. For my roommate, it was the belt. For the younger generations of the family depicted in “Yit, Ngay (One, Two),” it was the broom handle or a vacuum cleaner attachment. Although I never felt the sting of the wooden spoon, the threat it held is apparent in the voice of Alison Ahn ’03, one of the most powerful forces to hit the Nick Chapel stage for quite some time.

Spectacularly acted and sparely but powerfully staged, “Yit, Ngay” — written and directed by Michael Lew ’03 — addresses the beautiful and particular idiosyncrasies of a single family, both comic and poignant. The play achieves that most difficult of goals — a sense of universality through the telling of a very specific story. Most remarkable is that the entire story is told by a single actress alone on a stage with minimal props and simple lighting.

The ascending first act and the descending second find clever visual expression in four numbered cards hung from a clothes-drying rack where the single actress’s onstage costume changes take place. Numbered in Chinese characters, each card represents one of the four sisters. When the cards are folded down to the audience, they indicate which one of Ahn’s four characters will emerge from her fascinatingly malleable features. When they are folded down in pairs, we see ingeniously staged dialogues between two of the four strong female personalities.

The four sisters were separated when their parents moved to Fresno, California, with the youngest two daughters, while the two eldest remained in Toi San, China, to witness atrocities and suffer poverty and hunger. In China, the elder sisters received money and news from their restaurateur parents and increasingly Westernized younger sisters, who became doctors and married white men.

Culled from different points in the shared family history, the play nevertheless tells a coherent story and possesses a comprehensible chronology. The cards numbering the sisters and the scenes are a great help in creating this sense of order, and are believable and necessary components of the production. Careful direction ensured that the cards were never obnoxious or gimmicky, and always understated.

It is difficult to approach such an ambitious production without some trepidation as to the possibility of its ever being pulled off, but any doubts I had were destroyed by the immediate magnetism of Ahn and the increasing complexity and honesty of the play. Basing one’s entire vision on the credibility of a single actress is a gutsy move, but Lew has written a brilliant play and chosen the perfect star to carry it.

Lew’s play deals in the familiar trade of Chinese-American crises of cultural identity, worries over miscegenation, and memory of the violence from which many Chinese escaped in their sometimes-mad dash toward America. But Lew handles these cliches with such hateful love (the true indicator of any believable family), comfortably inappropriate humor, and thorough understanding, that it not surprising to learn that the play depicts Lew’s mother and aunts. By the end of the performance, the audience can’t help but be touched by his painfully honest portrayal of these wild women he must love so well.

Lew’s own intimacy with these beautiful banshees must have had something to do with casting Ahn, who sparkles with malevolence, horror, unswerving devotion, mischief, admiration and haughtiness throughout the course of her four characters and countless scenes. Playing one character believably is difficult enough, but convincing an audience that you are both characters in one scene is nearly impossible. Ahn succeeds, of course, even when different pairs of the four sisters are throwing spitballs, spitting watermelon seeds at each other, wrestling, teasing, or arguing.

Ahn is not only required to maintain her excellent diction, but must also call on her exceptional ability to act with every limb she possesses. Her movement is as expressive as her face, and through careful manipulation of both, the audience can’t help but believe the complex interactions of these four very different sisters.

As the play moves from one all the way up to four — scenes and sisters — and back again, the audience feels pleasured by a long, considered inhalation and exhalation of what it has seen and heard. The youngest sister, Karen, ends the play with her delicate consideration of the peaceful rocking of cradles, porch swings and park swings. Expertly and with a thankfully light touch, the rhythmic framework of the play is echoed by the steady swinging, all “something so primordially pleasurable, it must date back to the mother’s womb.” This is the kind of universality that can only be expressed through the specificity of park swings in Fresno, pushed by Karen, one of the many faces of the astonishing Alison Ahn.