Don't you just love to hate lawyers? Especially ones who'll do anything to win, no matter how low or nasty? As dramatic characters, they don't come much better than killer-instinct attorneys. But then don't you hate it even more when, just at their most reprehensible, they inadvertently reveal their own tortured humanity? Suddenly they're understandable. Maybe even sympathetic.

Bit of a moral dilemma, isn't it?

You don't quite feel that in "I Cry Aloud: The Clarence Darrow Story," a new one-man play receiving its world premiere at American Century Theater, but the show certainly wants you to. The material is legendary. Darrow is the turn-of-the-century labor and criminal defense counsel whose career included famously defending a Tennessee high school teacher, John T. Scopes, who had broken state law by teaching evolution, as well as saving "intellectual-thrill" murderers Leopold and Loeb from the death penalty.

Part of the problem is that the script--hastily assembled by Jack Marshall and Terry Kester--is still unwieldy and dramatically shapeless. Paul Morella, who gored audiences on both horns of that dilemma with his no-holds-barred portrayal of Roy Cohn in Signature Theatre's production of "Angels in America" last season, plays Darrow impeccably. But it's the kind of performance that leaves you wishing he had a more fully developed and defined role to perform.

Originally planning to produce David Rintels's 1974 play, "Clarence Darrow," ACT lost the rights less than two months from the scheduled opening. The theater decided to create and mount its own version of Darrow, drawing on recent scholarship that, unlike Rintels, shows the famous lawyer-crusader as a flawed human being capable of truly low deeds.

Using the frame of Darrow talking to us from a courtroom as he recounts his life and significant cases, Marshall and Kester draw a fairly complex picture of a man who begins his career with more or less noble intentions, sinks ignobly and is redeemed through a trial of his own. The trouble is the narrative is more literary than dramatic: Particularly in the first half of the two-hour-plus evening, Darrow tells us about case . . . after case . . . after case . . . with little insight into the enduring effect they had on him. There's no sense of tension building or character developing, just a man telling war stories.

Later the authors fare much better, often showing us a man stretched between idealistic ends and the cynical means he uses to achieve them. These moments are absorbing because the character, as written and played, forces you to take or leave him as he is, and neither choice is easy. Sometimes, though, Marshall and Kester's Darrow explains himself to us, as if hoping we'll see his side. This treads dangerously close to sentimentality, something you suspect Darrow himself would have despised. As a result, the trial the show concludes with--the notorious Leopold and Loeb case, still morally ambiguous and confounding--feels oversimplified.

Morella and Kester, who also directs, do their best work when Darrow merely outlines the situation he was in, recounts unapologetically what he did, why he did it, and then reflects on its meaning. Though he does have his grand moments, Morella is very good here at conveying a lot of emotion with minimal fuss, and his fluidity in the role seems natural, almost effortless. Despite the occasional attempt at presenting a likable Darrow, Kester deserves a nod for orchestrating a clean performance.

Costume designer Anita H. Miller's period suit for Darrow feels absolutely right, as does Kester's set design (except for a gallows that stands separately from the courtroom, a little spotlit island of melodrama that adds nothing). Still, impressive as it is for having been put together on extremely short notice, the overall production is best considered as a work in progress.

I Cry Aloud: The Clarence Darrow Story, by Jack Marshall and Terry Kester. Directed by Terry Kester. Sound, Bill Wisniewski; lighting, Marc A. Wright. At American Century Theater through Feb. 5. Call 703-553-8782.