To see Natalie Portman on the stage of the Music Box Theater is to understand what Proust meant when he spoke of girls in flower. Ms. Portman, a film actress making her Broadway debut, is only 16, and despite her precocious resume, she gives off a pure rosebud freshness that can't be faked. There is ineffable grace in her awkwardness, and her very skin seems to glow with the promise of miraculous transformations.

That the fate of the character Ms. Portman portrays is known in advance by most of her audience turns that radiance into something that is also infinitely chilling, however, and you may even feel guilty about basking in the warmth of a flame that you realize will be horribly and abruptly extinguished.

Ms. Portman has the title role in the new production of "The Diary of Anne Frank, " the dramatization of the legendary journals of a Jewish girl hiding from the Nazis in Amsterdam. And whatever the shortcomings of Ms. Portman's performance and the production itself, which opened Thursday night, the evening never lets us forget the inhuman darkness waiting to claim its incandescently human heroine.

This version, adapted (which in this instance means almost entirely rewritten) by Wendy Kesselman from Frances Goodrich and Albert Hackett's 1955 script and directed by James Lapine, offers no treacly consolations about the triumph of the spirit. Indeed, the effect is more like watching a vibrant, exquisite fawn seen through the lens of a hunter's rifle.

An uncompromising steadiness of gaze, embedded in a bleak sense of historical context, is the strongest element in a production more notable for its moral conscientiousness than for theatrical inspiration. This version is undeniably moving, with snuffles and sobs from the audience beginning well before the first act is over, and there are beautifully drawn, organic-seeming moments throughout.

Yet in portraying the denizens of the now famous "secret annex," the actors, who include such top-of-the-line veterans as Linda Lavin and George Hearn, don't always project the sense of a unified ensemble; it is often as if they had set their performances to different metronomes, when the feeling of a natural flow of time is essential.

As a consequence, the production can at times seem little more than serviceable. And yet somehow with this work, particularly as Ms. Kesselman has reshaped it, serviceable can be enough. The horror of its central situation, and the natural dramatic tightness it lends itself to, continue to hold the attention with an iron clamp. It also doesn't hurt that many people who see the play bring their own resonant associations with the diary. Clear, honorable and workmanlike, this "Anne Frank" doesn't achieve greatness in itself. But it doesn't diminish the magnitude of the events behind it.

It should be noted that "Anne Frank" returns to Broadway with an unwieldy load of polemical baggage, including furious debates over the diaries' appropriation as a pop commodity. The most resounding salvo was fired two months ago in an essay in The New Yorker by the novelist and critic Cynthia Ozick, who argued that Anne Frank's journals had been "infantilized, Americanized, homogenized, sentimentalized," especially in their translation to the stage. "In celebrating Anne Frank's years in the secret annex," Ms. Ozick wrote, "the nature and meaning of her death has been, in effect, forestalled."

Ms. Kesselman's reworking of the original script, which incorporates new material from the complete editions of the diaries made available in the last decade, goes a long way in redressing such objections. The Goodrich-Hackett script, under the director Garson Kanin's supervision, had bleached out much of its source's specific ethnic content for fear of alienating mainstream audiences. Correspondingly, the unspeakable destiny that awaited Anne was eclipsed by a disproportionate emphasis on the girl's idealism.

This new interpretation never relaxes its awareness of the hostile world beyond the attic that was the Franks' sanctuary and prison for two claustrophobic years, nor of the religious identity that made them a quarry. The earlier version began in a scene of sentimental hindsight, with Anne's father discovering her diaries; this one leaps, with a gripping immediacy, into medias res.

Adrianne Lobel's set, modeled as closely as the Music Box permits on the rooms behind Otto Frank's offices where the family lived, is in full view when we arrive. And for any reader of the diaries, it is hauntingly eloquent before any actor appears.

So is the entrance of the Franks themselves: Otto (Hearn); his wife, Edith (Sophie Hayden), and their daughters, Margot (Missy Yager) and Ms. Portman's Anne, who arrive onstage wet and disoriented from the rainy trip to their new home. As they turn to us, struggling out of their coats, the large yellow stars sewn onto their clothes are suddenly, glaringly visible.

It's a wonderful piece of staging, unforced yet emphatic; it establishes Judaism, and the ways it is perceived, as the Franks' central defining identity. "Look, it's still there," says Anne of the shadow of the star that remains after she has torn it off.

Indeed. Perplexed, often defiant references to what it means to be a Jew in the occupied Netherlands abound in the diaries, and Ms. Kesselman has incorporated as many as time allows: from Anne's catalogue of the activities forbidden Jews in Amsterdam to her vision of a former classmate in a concentration camp. The evolving sophistication of her writing about the world around her is far more evident now. So is her lyrical consideration of her burgeoning sexuality, and Ms. Kesselman has included a beautiful passage, nicely read by Ms. Portman, in which the girl describes the transporting effects of pictures of female nudes in art books.

As welcome as these additions are, one wishes that the voice-overs in which many of them are delivered had been less clumsily amplified. The effect is bizarre, as if Anne had found a public-address system in that attic. And there is also the sense that in combing through the rich trove of the unedited diaries, Ms. Kesselman was hard put to select just what to use. There is an occasional feeling of material being shoehorned in and confusingly truncated.

This gives the production a fragmentary quality its predecessor didn't have. Lapine's staging doesn't always accommodate the lapses from slice-of-life naturalism, though there are moments throughout, particularly among the younger actors, where everything clicks into place. And the climactic scene that finds the characters festively eating strawberries just before they are captured is everything it should be: a wrenching but impeccably rendered fall from what has become ordinary life into perdition.

Presumably, with further time the talented cast -- which includes Ms. Lavin, Harris Yulin, Austin Pendleton and the young Jonathan Kaplan as the other inhabitants of the annex -- will grow into a more comfortable ensemble. As it is, all the actors reach isolated, individual heights, most notably in the second act, when the stress of confinement finally brings out the Darwinian animal in everyone.

But in the first act, the performers are still oddly stiff as a team, and there's a sense, in ways that go beyond their characters' discomfort with unfamiliar circumstances, that they have yet to find a shared rhythm.

As the endlessly patient father, Hearn has an expressly theatrical, heroic voice and carriage that don't provide the troubled, affectionate shading to convey his all-important relationship with Anne. Ms. Lavin brings an impressive technical bravura to the role of the vain, anxious Mrs. Van Dam that achieves some splendid effects, as in a stunning new monologue for the character, and others that seem artificially calculated.

Pendleton appears slightly at sea as the graceless dentist who is forced to share Anne's room (though the scene in which she introduces him to their sleeping quarters is charming). Yulin, as the cynical, self-serving Van Dam, and Ms. Hayden, as Anne's fragile mother, are better in conveying, in very different ways, the aura of the older, more genteel world that shaped their characters.

Ms. Yager and Kaplan, as the Van Dam son with whom Anne discovers love, provide affectingly restrained portraits of adolescence cramped and frustrated by circumstance. Ms. Portman's comparative lack of stage experience shows, but in a strange way, this works to her advantage.

Even when her line readings are stilted, her delicately expressive face never fails her. It becomes, as it should, the evening's barometer of the changing moods in the annex. She has, moreover, an endlessly poignant quality of spontaneity, and of boundless energy in search of an outlet, that is subtly modulated as the evening goes on.

In Philip Roth's short novel "The Ghost Writer," the narrator speaks of Anne the writer in her diaries. "It's like watching an accelerated film of a fetus sprouting a face," he says. Without ever toning down her innate vitality, Ms. Portman does indeed progress from self-centered girlishness to the cusp of self -aware womanhood. To learn again that she will not be allowed to go further still shatters the heart.