Two years ago, the painter Tomma Abts walked away with the Turner Prize, one of the art world’s most prestigious awards. Just before Abts’s victory, which was something of an upset, Sarah Thornton found herself perplexed by the nature of the award: “I’ve experienced a ... chicken-and-egg confusion about the prize’s ability to reflect or create a defining sense of the moment,” she writes in Seven Days in the Art World, published this month by W. W. Norton. “It finally hit me that it’s vital for the prize to do both.” Thornton’s observation could also apply to her own book. Like any document devoted to an era, her insightful look at the art world during an unprecedented boom both reflects its subject and does much to define it.

Throughout the book, Thornton, a London-based sociologist who has written for the New Yorker and Artforum, welds together a handful of narratives that get under the art world’s hood to show how its complex machinery really functions. She devotes each chapter to a different affair, from her behind-the-scenes look at the Turner to a “crit” in artist Michael Asher’s legendary poststudio class at CalArts. She explores the porous boundaries between art’s commercial and noncommercial sides by taking the reader inside explicitly money-driven events, such as the 37th edition of Art Basel, as well as to rituals, like the Venice Biennale, that are supposedly untouched by the market.

The glue binding the book together is Thornton, who describes herself more as cat on the prowl than fly on the wall. As a result of her aggressive approach, her writing is peppered with the spot-on characterizations that also make good fiction worth reading. Artist John Baldessari evokes “God—a hippie version of Michelangelo’s representation of the grand old man in the Sistine Chapel.” The CalArts building where the grad-school crit takes place “feels like an underground bunker meant to protect those within from the mindless seductions of the Southern California sun.” Moreover, her level of access is enviable. An appendix lists the 250-plus players she interviewed, among them the art consultant Sandy Heller, who works with the hedge funder Steve Cohen and the L.A. dealers and Murakami agents Tim Blum and Jeff Poe.

Thornton isn’t the first writer to shine a light on the art world, a bipolar organism that revels in the flashbulbs of celebrity but retreats to inner, shades-drawn rooms to do its deals. Her book belongs on the shelf next to the journalist Anthony Haden-Guest’s True Colors: The Real Life of the Art World, a 1998 text that reads like a history of the contemporary-art market as told by a quidnunc. Both books open with an auction—Haden-Guest’s with the famous Scull sale of 1973 and Thornton’s with a 2004 Christie’s contemporary evening sale when the house hammered down Warhol’s Mustard Race Riot for $15.1 million—and go on to tell multivalent tales of art world desire and ambition.

In a short, somewhat preening video on her Web site, Thornton makes much of the fact that the book’s title is misleading. Though arranged as if it covers seven days, she wrote it over the five years, from 2002 to 2007, when the art market took off like a torpedo and museum attendance shot into the stratosphere. These dizzying developments may account for the frothy giddiness that at times characterizes Thornton’s first-person narration. Yet her wide-eyed gaze does not fall on the kind of tawdriness found in Haden-Guest’s book, which looked—somewhat darkly—at a boom after its bust. While in Thornton’s account we find a few seemingly confused young Conceptualists in Asher’s class and a couple of artists jaded by the market, we are never in a dive bar at 1:00 a.m., with Jean-Michel Basquiat, withered, high, missing a tooth and mere hours from his death by heroin overdose, as we are in True Colors. Seven Days in the Art World is, in fact, altogether free of tragic figures—a symptom of its looking only at the upper echelons. Or perhaps Thornton, who deems herself a “participant observer,” has eschewed complete objectivity for the thrill of the ride.