Grand Central Publishing.

464 pp. $24.99

Every year, the lament begins before the first day of summer, rising into the fall as high school seniors labor on their college applications. The selection process that makes sane parents crazy and stellar students insecure has been demystified (if made more frenzied) by the industry of books and workshops and private counselors selling advice on how to get past the gatekeepers.

But admissions officers (with their deliberately distancing title) remain unknown: an impenetrable column of representatives at a college fair, all using identical gestures as they break down the benefits of attending X College or Y University. To ask what they are looking for is to ask who they are - which, because they seem as inseparable from their institutions as the official seal, no one ever does.

It's this question, though, that interests Jean Hanff Korelitz in Admission, a skillfully subversive novel that employs a fictional landscape of the Princeton University Office of Admission to reveal not just the process of selection but also the persons behind the process.

One person in particular: 38-year-old Portia Nathan, recently promoted to covering the coveted "feeder schools" of New England after five years of red-eye recruitment trips to and from the West Coast. "I thought you needed a little shaking up," Clarence Porter, the dean of admission, tells her - and indeed, the geographical shift back to her home turf sends tremors through Portia's professional and personal life.

Competent at her job, comfortably partnered with a Princeton English professor, Portia is immersed in talented students' progress reports - but immobilized by a secret decision she made as a Dartmouth undergrad. Since then, she's cultivated a talent for isolation and found refuge in the relentless cycle of admissions (travel season, reading season, heartbreak season), which allows her intimacy with paper lives and distance from living reminders of what she can't admit she's done.

What, the reader wonders as Portia wades through all that potential, is she looking for?

Korelitz, who served as a part-time reader for Princeton during the 2006 and 2007 admissions seasons, gets the details of the work just right: the protocol for private school recruitment; the bunkerlike mentality (and deteriorating hygiene) that pervades reading season; the unstoppable stream of folders piled on Portia's desk, packed into her travel bag, and scattered across her bed.

Like her protagonist, Korelitz understands the symbolic power of the application file room: to parents, the "holding pen where their child and all his or her antagonists were gathered"; to Portia, a library of stories waiting to be read. And she improves the image of every A.O. by inviting readers to committee meetings, where agonized, "scrupulously fair" decisions are made. In the novel and in my experience, the field doesn't attract the evil nay-sayers of legend and nightmare, but rather, do-gooders who seek to change lives by opening the gate.

What I found most moving about the novel is the way Portia's past resonates with the present in the applications she reviews. "Already, just in her first term," Korelitz writes of Portia's freshman year, "she had tasted and spat out too many potential selves, learning only what she was not and did not want, but never what she was or did."

In the "excerpts" of earnest essays that herald each chapter, we're introduced to the prospects that compete for Portia's advocacy. These are the voices of today's teenagers trying on ideas and attitudes and ambition for size, making Portia a ghost.

This eerie double take on adolescence - familiar to anyone who has relived past trauma while counseling a child - is emotionally true and, in my view, excuses a plot point that relies on coincidence.

The college selection system matters - to legacy and first-generation applicants alike - because it shapes preparation into the form that garners reward. The revelation of Admission, which Portia is compelled by her position to explain to her partner, Princeton faculty members, and exasperated parents, is that "the much-maligned system . . . was not about the applicant at all. It was about the institution. It was about delivering to the trustees, and to a lesser extent the faculty, a United Nations of scholars, an Olympiad of athletes, a conservatory of artists and musicians, a Great Society of strivers, and a treasury of riches so idiosyncratic and ill defined that the Office of Admission would not know how to go about looking for them and could not hope to find them if they suddenly stopped turning up of their own accord."

When Portia stumbles upon Jeremiah - a brilliant autodidact with a disastrous transcript at the experimental Quest School - Korelitz finds the conflict at the heart of selective admissions: the poetic versus the prudential student, the well-rounded kid versus the lopsided genius, the "professional" student ("The Organization Kid" of David Brooks' 2001 essay about Princeton) versus the untamed intellect following his or her curiosity.

Portia prepares for final committee as if preparing for trial, gathering evidence for Jeremiah's future success and strategically ordering his case among others she's willing to lose. Admission succeeds because like a persuasive application essay - the kind we joyfully shared around the office at Bryn Mawr - Korelitz reveals what she values through what Portia defends. She makes the personal universal by connecting her character's dilemma to larger issues that concern us all: how we will educate our children and how we want to live.