UNSEXED.

The evil that men do is nothing without an audience to witness it. The dictator works the crowd in order to see his power in action. The rapist gets off on the panic in his victim's eyes. For the smilers with knives, there is no "I" without the spectator whom they forcibly seize and then abandon, blood marking the spot.

Blood punctuates so many of the melancholy, twisted events in Shakespeare's "Macbeth" (now in a Public Theatre production at the Delacorte) that it's as much a character in the play as the fantastical and potent Weird Sisters. And, like those creatures, who are "So withered and so wild in their attire / They look not like th' inhabitants o' the' earth / And yet are on't," the blood that Macbeth spills in his pursuit of power speaks of and to his ultimately unconquerable guilt, his inevitable haunting. "Blood will have blood," Macbeth (Liev Schreiber) announces to his wife (Jennifer Ehle) as they sit through the night contemplating their joint wrongdoings. This conflicted, nefarious pair aren't especially interested in shedding light on their dark souls, however; each is as self-absorbed and shortsighted as the other. Instead, they struggle to cast off all moral consciousness. But even Macbeth knows that his night visions can't be shut out; for this "secret'st man of blood," darkness draws truth to the surface.

As it happens, nowhere in "Macbeth" is blood blood. That is, family is nothing but a collection of false loyalties that can be realigned or wiped away in an instant. And it is the idea of the Macbeths as a fractured political family that the prodigiously gifted director, Moises Kaufman, plumbs again and again here--that, and the notion of what constitutes the masculine and the feminine. These themes have preoccupied Kaufman for some time. As the writer and director of "Gross Indecency: The Three Trials of Oscar Wilde" (1997) and "The Laramie Project" (2000), and the director of Doug Wright's 2004 Pulitzer Prize-winning play "I Am My Own Wife," Kaufman made it clear that his intellectual interests lie in "queer" culture's reinterpretations of male and female.

In Ehle, he has a willing collaborator. At the start of the play, Lady Macbeth receives a letter that her husband, a legendarily fierce Scottish general, has sent from the front, where he has helped save Scotland from a hostile takeover by the King of Norway. Macbeth tells her of the Weird Sisters' prophecy that he will one day be king. As she reads, Lady Macbeth finds herself dreaming of the blood yet to be spilled--of the rivers that will flow if only she can guide Macbeth to power. The blood that will stain her husband's hands is less offensive to her than her own menstrual blood--the symbol of her femininity. "Unsex me here, / And fill me from the crown to the toe top-full / Of direst cruelty!" she says. "Make thick my blood; / Stop up th'access and passage to remorse, / That no compunctious visitings of nature / Shake my fell purpose."

While delivering this speech, Ehle runs her fingers lightly up and down her midsection, in order to make it clear to us that she is speaking of Lady Macbeth's womb. This graphic, almost cartoonish gesture passes in a flash. And yet it manages to stick in the viewer's mind, if only because of its awkward charm: Ehle's interpretation of the role stresses not Lady Macbeth's cold focus but her odd vulnerability. Dressed like a nineteen-fifties sitcom mom--her skirts are big and full, her blond curls clean and tight--Ehle is the very image of sweetness. As Elizabeth Bennet in the 1995 BBC version of "Pride and Prejudice," and as the star of Istvan Szabo's underrated 1999 film "Sunshine," she projected a similar flowerlike tenderness. While Ehle's Lady Macbeth is a stretch--and an act of defiance against the standard casting of the role--you root for her, if only because Kaufman is rooting for her, too. Rather than downplaying Ehle's decency and beauty, he folds that honey into Lady Macbeth's malevolence and bile. Ehle, in the role, becomes the kind of old-fashioned woman who is happy to step back and pass the canapes ...