Recently my husband and I passed a balding man on his cell phone as we parked our grocery cart by the frozen TV dinners.

"It wasn't her fault," the man said into his phone.

My husband turned to me. "Maybe it was her fault."

A few days later, I passed a young, jeans-clad woman sobbing into her cell phone as she walked down a city street. Overcome by grief, she squatted on the sidewalk and leaned against a glass storefront, the hiccupy sobs into her phone reaching a fever pitch. I was struck by an intense desire to ask her what the matter was, and to offer comfort ("The bastard!" I was preparing to say). I did nothing.

Sarah, however, the protagonist of my novel, might well have intervened, the veneer of restraint holding most of us in check having grown thin and flimsy around Sarah's sensitized, easily stimulated core. In a world where terrorist chatter merges with the scream of sirens, cell phones, TV, overheard conversations, and war, Sarah fights chatter with chatter.

Am I Sarah?

I've never taken a lover (well, in this marriage), and my husband has no children from his Peace Corps days. I have leafed through items on his bureau while pretending to be in search of something else, I have skewed the truth when full frontal would seem a dangerous blow to marital concord.

Like Sarah, I don't cook during wars, and have never used the oven in our current apartment. Like Sarah, I long to do good in the world, but reach for Dove Bars instead. Like Sarah might have done, I've engaged in small talk at a cocktail party in a large room with a dark-haired man from a violence-racked nation and never mentioned the elephant. Like Sarah, I'm besotted with my dog because . . . who wouldn't be.

My husband has suggested I write a section of this essay titled "Why Jacob?" Jacob is "the other man" in the novel, from whom Sarah draws succor when Michael, her husband, seems to come up short, but I made Jacob up.

Is my husband Michael? Only on his most explosive days. A novel suffused with tender moments and selfless acts on the part of a major player would lull us to sleep. That's what I tell my husband. Once when my husband and I were dating we were going to meet a Peace Corps friend of his for dinner, and my husband was nervous and said to me, "I'll guide the conversation."

My husband has played an important role in this book. He once knew a man who received a phone call from an adult son he never knew he had from his years in Vietnam. The man met with the son, then with the son's mother; eventually he left his wife and other children and moved in with the Vietnamese woman. You'll see the connection with Chatter.

My relationship to the Vietnam War is the same as Sarah's. It's not true all baby boomers were hippies in the sixties.

Like Sarah, I've had friends with cancer. Some survived and some did not, and all are braver than I.

Like Sarah, I sometimes romanticize poets, who are actually dreadful people, my friend Liam tells me.

It's true my husband gets all of his secretary's diseases. I don't worry about this.

Other things in the book you may want to know the truth of:

I'm ambivalent about shrinks. I've had some good ones, but my friends haven't because they don't change.

I've used tranquilizers on planes. Ninety-five percent of the people on planes are drugged but we don't find out until there's an incident and they explain about taking a drink on top of the drug. I don't take the drink and there have been no incidents.

I once saw a man on a bus reading How to Love Your Teenager. The bus was leaving the Pentagon and I thought trouble upon trouble.

When people read the scene about what happened to Random, the dog, in the park, they talk about Sarah over-reacting. You've got to be kidding.

The first draft of my book included a brilliant riff on how rich women inevitably become bitches through no fault of their own, but my editor cut it out.

Am I Sarah? Sarah is scattershot, and rambles. She has a vivid imagination.

An alarm is sounding, the phone is ringing, a newly arrived e-mail is dinging, and on television the president begins an unscheduled announcement.

This is the sort of thing that frightens Sarah.

My hand trembles as I pull out the atlas to look up Iran. ▣