“Indecision,” Benjamin Kunkel’s debut novel, seems awfully heavy for a trim, quick-paced 240 page book. Maybe that’s because the book is bogged down by the hope and hype surrounding it. After all, Kunkel is a young, handsome, accomplished Harvard grad. NYC literati like Jay McInerney have already anointed Kunkel as a new voice for a new generation, one that went to bed sly and sardonic and woke up surrounded by disaster that defies irony.

It’s a lot to expect from a book whose plot is thinner than a fingernail. But suave Kunkel plays the part admirably. He has crafted a narrator, Dwight Wilmerding, inert and content. He falls squarely among the classic, preppy-prolix American voices: he would be Holden Caulfield if Holden had simply stayed in school; Nick Carraway if Nick hadn’t met Gatsby; Huck Finn if Huck Finn liked ecstasy and abulinix.

And just what is Abulinix? The drug — Kunkel’s creation — catalyzes the novel and its protagonist. It cures indecision, the woe of so many contemporary young men, according to Dwight’s roommate Dan. The cornucopia of choice afforded our generation has left us paralyzed, Dan thinks.

“Here in New York,” Dwight says, with the laziness and self-obsession of the worst Ivy Leaguers, “I have been mistaking the commotion for my own.”

On the drug, Dwight resolves to travel to Quito, Ecuador to visit Natasha, his prep school love. She leaves right after he arrives, but it isn’t long before he shacks up with Brigid, a Belgian Democratic Socialist. What happens between these two, once they are left alone in the jungle, is fairly predictable. For illustrative purposes, let’s just say that page 214 contains the decorative simile “ejaculating like a garden hose.”

Up until that point, the novel is essentially a journey through the third world trailblazed by a man who flips coins to decide even the most inane decisions. Dwight, ever uninspired, cannot commit — and Kunkel can’t either, instead settling for describing the transient pleasures of a pretty location and pretty companions like women and drugs.

His writing, decadent and distracted, frankly leaves a lot to be desired. Perhaps the sole exception is a sublime scene describing an ecstasy-fueled orgy that ends with planes crashing into the twin towers. Here his writing is slow and surprising; the power of his clean and honest prose makes up for its uneven juxtaposition of excessive hedonism and extreme hysteria.

This is the power that Kunkel taps into for the book’s conclusion. The final chapters are narrated with epileptic energy and messianic ambition. His writing, right when it counts, is all the things good literature needs to be: ecstatic, revelatory, angry and affectionate.

Kunkel sheds and then shreds his influences, finally abandoning “Catcher in the Rye” as his model for the coming-of-age story. Whereas Holden Caulfield wanted to leave the world alone — and for it, in turn, to let him and his sister be — Dwight arrives at his high school’s 10-year reunion with nothing but love. “You’re all beautiful,” he cries, ending a meandering, well-meant toast that demands the near-30-somethings begin helping the world’s poor.

“Maybe not morally. But so well groomed” he adds with the harmless idealism of a vigilant convert to Democratic Socialism.

In “The New York Times,” Mr. McInerney dubbed “Indecision” a post-ironic novel for a post-ironic world. In truth, it is soaked in the same irony and playfulness that fans of David Eggers and Jonathan Safran Foer find irresistible. Like these peers, Kunkel bows down before the alter of buoyant, lovely language. As a result, he lacks the richness that comes with a more mature embrace of characterization and plot. Solipsism and short attention spans send the very ingredients of a good novel straight to second-class status.

Yet Kunkel — young, interested and interesting — deserves a reader’s patience. You’ll be well rewarded for peeling away the thin surface film of adventure and romance and probing past the adolescent narrative voice. The last 50 pages of the novel have enough meat, marrow and muscle to give the novel a form worth admiring.

As its hero promises in its opening pages, the novel does its darnedest to offer a “final prescription for what the whole world needs.” If only Dwight Wilmerding had half of Benjamin Kunkel’s conviction.