With sharp wit, a debut novel skewers investment bankers, high society

Mergers and Acquisitions, By Dana Vachon, Riverhead, 290 pp., $23.95

A preppy young wag with the world ahead of him, Tommy Quinn is no one's hard-luck poster boy. But things aren't entirely what they seem for the hero of "Mergers and Acquisitions," a funny, garrulous romp through moneyed Manhattan.

The opening chapter of Dana Vachon's first novel so dazzles and confuses the reader with unconnected bits of narrative, salty sexual innuendo, and references to Lindsay Lohan, Paris Hilton, and other faux-celebs that it almost derails all interest. But once he settles into Tommy's story, Vachon lets rip with a charming, if far-fetched, tale of the problems of privilege.

Tommy, a country-club brat from Westchester County whose premed course of college study yielded exactly one medical school acceptance (in Costa Rica), starts his working life in the analysts' training program at J. S. Spenser , a venerable investment bank in Manhattan -- through his father's connections, of course. The rich, it seems, are very different from you and me.

"My graduating class at Georgetown was full of future bankers. As friends got jobs at Goldman and Lehman and CSFB, signing bonuses were wired into college checking accounts, then converted into elaborately themed parties to celebrate gainful employment. One friend turned his house into Studio 54. Another experimented with irony, and had a local caterer affect a large Italian wedding."

With no head for numbers and no knack for faking it, Tommy makes his wayward progress with help from fellow trainee Roger Thorne, a star-obsessed babe hound whose function as the hero's foil is reminiscent of Tad in Jay McInerney's "Bright Lights, Big City." Roger's overheated male adolescence makes Tommy look like a saint.

" 'Did you know that Lilliana and Sylvana are bisexual, but only with each other?' [Roger] asked, as he handed me my third gin and tonic and pointed to a pair of Hermes-clad Latin women just across the room."

Vachon obviously had a grand time living through Roger's sexual adventures -- and almost as much fun portraying his female characters as a pack of mannequins. Tommy is in love with a fragile debutante and art student named Frances, who inexplicably drops out of New York University because her stepmother is having a baby, whom she refers to as "the thing."

As Frances introduces Tommy to her friends, she turns out to be the only one in the group with any substance. "Next to Phoebe was Frances's other Choate friend, CeCe. With a head of blonde hair and a naturally golden complexion CeCe looked as Phoebe wanted to look, and seemed to know it. She worked as a publicist for Caroline Herrera , but carried herself as if she guarded the holy grail. From the first she gave me the impression that all of Manhattan was a large soiree, and that she made the guest list. She nodded to Frances that I passed muster, but perhaps only barely."

Though his own snob sensibilities give him away, Tommy's problem is the lack of purpose and meaning in his vapid, overindulged world. Despite their many funny, over-the-top predicaments, he, Frances, and Roger seem destined to land on their feet. As a result they may fail to linger in the mind of a reader who grows weary of being force-fed with a silver spoon.

The narrative is much more interesting and convincing when Vachon sticks to the investment banking world and its foibles. Getting into the right club or landing a Park Avenue address means more to the head of J. S. Spenser than firing an analyst for blowing a deal, as Tommy learns. But not before a bid to sell an unpromising oil field suddenly goes live, and his supervisor, an Indian math whiz from Cornell named Makkesh Makker, has to cover for him for botching a Canadian dollar conversion ("I broke new ground as a financial pioneer, the first and only man to ever successfully convert the US dollar to itself").

Vachon, who worked as an analyst for JP Morgan after graduating from Duke University, has taken the contemporary-experience-as-fodder approach to fiction, and it works. The pop-culture references will be out of date before the paperback version, and it's overlong and repetitive, but that doesn't mean that "Mergers and Acquisitions" won't make a great beach read in places like Bridgehampton and Marbella.

Amy Graves is a freelance writer living in Cambridge.