Occasionally, alone on the road in the middle of the night, a set of headlights in the rearview mirror can become, in my head, a psychotic policeman with an unstoppable, irrational scheme to plant drugs or a gun in my car and arrest me for resisting arrest: all for the sadistic kick of an easy hunt. Or maybe he'll even give me a speeding ticket. Certainly I don't really believe all this paranoia, but this imaginary psychopath suggests an authority amidst the chaos of my midnight highway that is, I might even say, comforting.

In the all too orderly world of Sheila McGough, every new face is another version of this policeman, another link in the vast conspiracy that held her prisoner in a cage of lies inside this country's system of justice. Some call it schizoid;, she just calls it getting by, since her career as a singularly dedicated lawyer was effectively ended by her conviction for colluding with a con-artist client to subvert her profession and violate the law. She spent years in prison after refusing to testify against this con man and only began to speak of the gross injustice Because this peculiar, intractable lawyer is the heroine of Janet Malcolm's new journalistic essay, The Crime of Sheila McGough, the book has a fascinating mystery at its heart: the search for truth in the shadows of the legal system. Malcolm is an excellent and witty tour guide through this material, some of the densest thickets of bureaucratic confusion this side of Kafka. After all, McGough's client was, in Malcolm's evocative retelling, a veritable genius at the art of the con: layering stories upon stories and constantly filing equally believable, contradictory documents in legal offices across the country. Without Malcolm's intelligent and clear prose as a beacon, anyone would be lost trying to understand the intricate activities presented in the work: shuttling funds among bank accounts, filing counterfeit documents, forging signatures, inventing associates, and selling bogus companies to a gang of equally disreputable businessmen."

The ingenious con schemes bring the text to life, and because Sheila McGough refuses to admit any wrong doing at the expense of either herself or her client, Malcolm finds her obstinate, even infuriating. Always self-analyzing, Malcolm emphasizes this dramatic battle between journalist and subject even as she elevates McGough as a compelling heroine. With a twinkle in her eye, Malcolm writes: "I don't know if I've ever had a more irritating subject...I have never before interrupted, lost patience with, spoken so unpleasantly to a subject as I have to Sheila."

At its worst (which, given Malcolm's excitement and insight as a journalist, isn't very bad), the book founders on Malcolm's signature theme: the biases of the journalist as a narrator who chooses sides in the fight over which stories are true. While her last book, The Silent Woman, used the controversy over the death and estate of the suicide poet Sylvia Plath to illuminate brilliantly these questions of authority, here the justice system becomes her battleground; lawyers dispute not over matters of law but something more beautiful and strange, the power of stories to overwhelm the truth. The lit-crit quibbling of this approach at times quickly becomes tedious. Still, these cerebral arguments pale beside Malcolm's acute character studies, little gems of quirk and nuance like an eccentric bolo tie on a dreary elderly gentleman that leavens the confusion of the story with humor and grace.

Because Malcolm's style emphasizes the investigations and interviews as that essence of her journalistic process, these perfect tangents and odd details tend to add up to something tangible. When she discovers inconsistencies among the documents and depositions, her words practically beam off the page: for an instant she transforms herself from cerebral commentator into Nancy Drew, and the excitement is infectious. In any case, though probably a minor work from this superior journalist,The Crime of Sheila McGoughfeels exceedingly comfortable, energetic, and lived in. This is no John Grisham thriller; instead, this may be the most innocently guilty pleasure for a while.