Murray's nephew, Bootie, a morose autodidact -- imagine Holden Caulfield with his nose in a book of Emerson's essays -- rounds out Messud's central cast, each illustrating Messud's acute understanding of the Peter Pan complex now rampant among young adults who feel entitled to be extraordinary: "To be your own person, to find your own style -- these were the quests of adolescence and young adulthood, pushed, in a youth-obsessed culture, well into middle age."

Not until page 370 of Messud's delicious depiction of the quintet's tangled lives, "torn between Big Ideas and a party," do the planes hit the towers. Bootie -- it could have been any of these people preoccupied with manufacturing interpretations of fashions and fashions of interpretations -- has "a fearful thought: you could make something inside your head, as huge and devastating as this, and spill it out into reality, make it really happen."Imagine that.

Before 9/11, Messud began writing a Manhattan novel about young adults living in the media hall of mirrors. After 9/11, she abandoned it. Then returned to it. Asked if she thought she had written a "9/11 novel," she demurs: "I wrote an August 1914 novel." Meaning, "The world I had set out to describe in 2001 had become historical."

But what had changed? The party, scheduled for 9/11, to launch the Australian's magazine and the revolution -- Renee Zellweger had accepted; Susan Sontag was a maybe -- was canceled, as was the magazine. Murray "formulated a reasoned middle ground": America did not deserve the attacks, but remember the West Bank. "He wasn't opposed to the invasion of Afghanistan, but qualified about its methods." Danielle decides to proceed with her liposuction documentary.

Nothing changes everything. And even huge events that, as Messud says, make "certain things seem particularly frivolous," leave most of our enveloping normality largely unscathed. That truth and a heightened sense of the frivolous are conducive to national poise five years into a long war.