The epilogue of Jill Lepore's "Joe Gould's Teeth" is a fever dream, a crazy-wild culmination of her quest for Gould's long-lost (if it existed at all) colossal oral history of the world. In the dream, she drifts past the hundreds of Holstein-colored composition books, rumored to hold the history; drifts past the kookier episodes in Gould's very kooky life. There is no touching in this dream, though she holds one possession: Gould's false teeth. She didn't unearth Gould's missing history, but she found his missing teeth. Not really. She left them on New Yorker writer Joseph Mitchell's desk anyway.

Mitchell, of course, perfected the New Yorker profile: "precise, tender, and sly, with God-given prose," writes Lepore. Some, like me, are drawn to his street smarts, nervy curiosity for life's sideshows, pride of polish — like a shoeshine boy finishing with a snap of the towel. He wrote two inimitable profiles, both about Joe Gould: 1942's "Professor Sea Gull" and 1964's "Joe Gould's Secret."

Gould was a man of the streets, a bohemian and a learned hand despite his shabby circumstances, who claimed to be writing "The Oral History of Our Time," which, it was said, occupied those uncounted composition books in Lepore's dream, though few ever saw their insides, and Mitchell — never.

Were they real, those hundreds of volumes of new history, or were they a figment? "I got interested in knowing if any of it was true," writes Lepore. Anyone who has read Lepore knows that, let loose in archives — library archives, archives of memory — she is crackerjack, squeezing into claustrophobic corners where the good stuff is found. Here, she returns with only random volumes of the "Oral History," if indeed they are that. She surfaces with different riches, profiles of her own, of Gould, Mitchell and sculptress Augusta Savage, a subject of Gould's uninvited advances.

Lepore charts Gould's fraught progress through Harvard (legacy admission), eugenicist period ("eminence was due, it seems to me, not as much to inherited ability as to inherited opportunity," he wrote — it's a wonder he escaped alive), prescient take on history ("I'll put down the informal history of the shirt-sleeved multitude … their jobs, love affairs, vittles, sprees, scrapes, and sorrows.") He was also a liar, mooch, groper, wickedly vindictive and weak on personal hygiene — a mentally ill institution (electroshocked, Lepore contemplates, lobotomized?). Gould haunts Lepore.

Mitchell recognized a mark, but he was taken by Gould, did not do his homework, then disgorged him: His second profile confessed to invention — Mitchell's Gould a confabulation, Gould's history "kitchen midden of hearsay." Like Gould, Mitchell had written a book in his head (undermining, perhaps, his confidence and wizardry). Savage is Gould's foil and fancy — her art was hard won and for all to see; Joe was sweet on her, but she could smell the sour on him — and her teaching of Harlem youths is still venerated. Savage is a vital counterpoint here, and Lepore seemingly plucks her story from the air, a sculpted piece of African-American experience all its own, but you know she found it in those cobwebby archives.

It is easy to get a charge out of this parti-colored, flabbergasting tale, one that typifies what Lepore understands as "the asymmetry of the historical record." In the noise and silences, with only the evidence at hand, our sleuth must discern the card-carrying account.

Peter Lewis is the book review editor at the Geographical Review.

Joe Gould's Teeth
By: Jill Lepore.
Publisher: Alfred A. Knopf, 235 pages, $24.95.