For a little while I led a double life. By day I was an earnest student, searching alongside my geology professor for life and oxygen in the murky waters of the remote, and aptly named, Lake Lonely. By night I was an anxious, love- struck pixie who craved the indoors, having found deep but illegal love with someone I shouldn't have. I liked living this way, half in the shadows; it made my 19-year-old life sensual, imbued with importance. But as the affair staggered to its inevitable end, I watched my night self pass gradually away. Now I marvel at the evidence that it ever was: notes, photos, a tiny, anatomically correct heart cast in pink plastic I was given as a gift.

Though I thought it was at the time, that double life of mine wasn't so unique. Who doesn't, in some way or another, have a secret self? We adapt and pretend; we have different personas for different occasions; the secret passions and plans we nurture in the long minutes before sleep often seem like those of someone else. So the characters in Jennifer Egan's rich new novel Look at Me–double lifers all–feel sort of familiar, despite the less-than-familiar circumstances that surround them. There's Moose Metcalf, a gentle if unhinged academic whose mental life constantly wars with his material one. There's Charlotte Hauser, Moose's 16-year-old niece, who conducts an illicit affair with a math teacher at night and halfheartedly attends high school during the day. And in the fore there's another, older Charlotte–Charlotte Swenson–an almost-supermodel who, having opted out of a double life early on, is shocked to find herself thrust into another. After surviving both a car crash that shattered every bone in her face and a series of reconstructive surgeries, Charlotte must design a new life, having been given a face that's unrecognizable not only to those from her past, but to her as well.

This Charlotte holds the center of Look at Me. Wryly, she narrates alternating chapters, revealing the day-to-day details of her recovery and a fragmented picture of her past, stringing us along to the novel's denouement–the explanation (and bizarre re-enactment) of Charlotte's car accident just outside her hometown of Rockford, Illinois. Though she declares, on page 1, "The truth is that I don't remember anything," she also lets on that she's not to be trusted. Preparing to meet a private detective who's investigating the disappearance of Z, a man Charlotte knew in her pre-accident days, she explains, "I would lie, of course. I lied a lot…. Telling someone a secret was like storing plutonium inside a sandwich bag; the information would inevitably outlive the friendship or love or trust in which you'd placed it. And then you would have given it away."

As she lazes on her sectional couch in a Manhattan highrise, smoking Merits and drinking before noon, Charlotte fans out the glitter of her spoiled life. "Photographers. 'You've got it!' Cocaine in tiny spoons, in amber vials. Expensive dinners no one touched." Her life full of images, empty of feelings. Still, "it had a lazy, naughty appeal, the allure of skipping dinner and eating a gallon of ice cream instead, of losing a whole weekend prone before the TV set."

But before jumping to conclusions, I'll warn that Look at Me shouldn't be lumped together with the skin-deep works of Bret Easton Ellis and Jay McInerney. Charlotte isn't your average fictional model. To the extent that she's obsessed with appearances, it's only to look for a person's "shadow self," the evidence of a double life, "that caricature that clings to each of us, revealing itself in odd moments when we laugh or fall still, staring brazenly from certain bad photographs." Usually, she spots it quickly; "when all else failed," she explains, "I found it by looking at people when they thought they couldn't be seen–when they hadn't arranged themselves for anyone."

Only the shadow self of Z, "one of those people whom it was impossible, and slightly unpleasant, to imagine in daylight," escapes her. Charlotte meets him in a crowded nightclub, assumes he's just another promoter making the model scene. But, uncannily enough, Z is actually a Hezbollah-trained terrorist–one who eerily conforms to all of our post-September 11 expectations. He leads the ultimate double existence, cruising Manhattan for targets by night and crashing in a cramped Jersey City apartment by day. He's Middle Eastern. He's made a career of slipping in and out of people's lives, vanishing and surfacing in points West. And "he hates–despises–America."

Disappointed with the results of the 1993 WTC bombing–"only seven people dead of the many thousands who worked in those buildings, seven including an unborn child! Structural damage completely underground"–Z sets about designing a new plot. "If the collective goal was to be seen–to saturate the airwaves with images of devastation that would serve as both a lesson and a warning–why not strike at the famous people themselves?" He fixates on Charlotte after recognizing her from a cosmetics ad on TV. "In that instant, his hatred and lust and longing to destroy, his regret over all he'd gouged from himself in the process, affixed themselves to this woman…. He imagined sinking his teeth into her lovely white arm." Charlotte, in turn, finds him mysterious, and attractive.

Given recent events, it's weird to find a character like Z in this book. But he's not Egan's first terrorist. In her beautiful, sad first novel, The Invisible Circus, Egan explored the idea of double identity through the phantom character of Faith O'Connor, a member of two terrorist sects active in Berlin in the early 1970s. As Faith's younger sister Phoebe scours Europe to understand the circumstances surrounding Faith's mysterious suicide, her detective mission evolves into one of reconciliation. How could Faith–who, as a young girl, had buried a rabbit she'd shot on a hunting trip in the backyard with a gravemarker reading "i am sorry, Bunny"–have been responsible for killing people?

Back in Rockford, a burned-out industrial town ninety miles west of Chicago, Charlotte Hauser inhabits a world opposite to that of Charlotte Swenson. She is not pretty or sardonic. She understands that there are "two worlds, and in one of them, everything was harder. No one came to you, and if you went to them, you were likely to be punished for it." Charlotte's life intersects with her namesake's in ways that I cannot disclose, but most of the time we see her in the company of older men: math teacher Michael West and her uncle Moose. She encourages Michael to seduce her, and they begin a sexual affair; around midnight a few times a week, she pedals her bike to his house. She asks Moose to tutor her, and they begin a different kind of affair; once a week, in the hours after school, she pedals to his office.

Despite her atypical taste in intimate relationships–"Moose, and Michael West. Her secret life. She gave up the rest."–Charlotte is not only a credible teenager, but a sort of typical one. She keeps a journal, recording her encounters with Michael in a girlish code: "N1T2"0412*//**KL1704 (November first; Thursday; raining; left at 12:04; returned at 4:17; with details of the visit sandwiched in between.)" She plays games with herself: "If he kisses me now, he loves me. If he smells my hair, he loves me." She demands that her "boyfriend" give her something, "anything." All this so that "later, when she was gripped by a fear that it might not be real–that it was nothing, had not even happened–she could…be calmed."

Moose, meanwhile, teaches Charlotte about history. Once a rising academic star, Moose now toils in disgrace at Rockford's Winnebago College; he was fired from Yale for endangering the lives of his students by giving them a "thought experiment" that involved real explosives. Each week he opens his small, subterranean office to Charlotte, or takes her on tours of the abandoned, decrepit downtown of Rockford, explaining the past lives of the rail station, the river, the grain elevator. He carries a small photo of the buildings that used to line the Rock River that runs through town for "evidence" of what the town once was. She writes papers and titles them ("How Two Machines Changed Everything About Grain," "Grass"); she recites dates on demand. She is pulled by a desire to please Moose, who ultimately mistakes her preoccupation with Michael West for a life-changing understanding of his own life's work.

Between Charlotte Hauser and Phoebe O'Connor and the young women she's reported on in various pieces for The New York Times Magazine, Egan could be the patron saint of teenagers. She draws young women as if they are her close sisters; Egan lets them err, she does not condescend to them, she respects their naïveté. The fact that she's had real access to real teenagers might help. Egan's reported stories for the Times have covered everything from girls who cut themselves (a theme explored in her short-story collection, Emerald City) to gay teen relationships over the Internet. The sad arc of Phoebe O'Connor's desperate sexual awakening in The Invisible Circus rings too true. In Look at Me, after a few visits to Michael West's, Charlotte feels

hurt inside, broken maybe, thinking, I'll never go back there, no one will ever know about it. But after two or three days her craving for him made her almost sick–to flee the tiny envelope of her life into the strange other world where he lived, to feel his hands on her. All of it.

Still, when Charlotte finally leaves her secret self behind to wear makeup and flirt with boys her own age and work at TCBY, we understand that this is part of her growing up; it's OK if she wants to be normal. Egan doesn't push.

Look at Me has not been universally praised (though it has been justly nominated for a National Book Award). It's true, Egan's characters are potentially dislikable, if not despicable. Look at them: They're liars, they're injurers, they take much for granted. Charlotte Swenson gets to live not only one lavish life as a fashion model but a second one, as a filthy-rich multimedia celebrity–just by being herself, online. Charlotte Hauser initiates an affair with a man twice her age. Z is, well, a terrorist. Moose is plain crazy.

But caring about the protagonists of Egan's book is beside the point, anyway (even though I liked them all). Look at Me is about bigger things: double lives; secret selves; the difficulty of really seeing anything in a world so flooded with images.

In an article for the online magazine Slate, Egan explained that with Look at Me she "set out to examine the impact of image culture on human identity." "How," Egan wondered, "has America's emphasis on display…altered the makeup of people's private selves?" By this book, the picture isn't pretty. Charlotte Swenson, whose entire adult life was constructed around her real and metaphorical images, has no private self. She has no interests or real friends or distinguishing characteristics, other than her ultra-dry wit. (Oh, and she loves to watch Unsolved Mysteries.) She's so bland, in fact, that although we know she was beautiful (a model, after all), we never really know what she looks like, before or after the accident. (With that gap to fill, I pictured her looking like Jennifer Egan, who, judging from her author photo, is glamorous enough to be a model herself.) As for Z, he has nothing but an idea for a picture.

Toward the end of Look at Me, Moose repeats the words "we are what we see" like a mantra. But what that means is that we aren't all that much. It doesn't matter how closely we look at each other, Egan shows us again and again, there's more that we can't see than we can.

And about that double life…. Two characters in Look at Me, both mentioned in this review, are actually the same person.