Many people lent their expertise to the writing of this book. I’d like to thank my friend and editor at Doubleday, Jason Kaufman, for his assistance in countless ways, large and small. Thanks also to his colleagues, Jenny Choi and Rachel Pace.

Kenneth Freundlich, Ph.D., provided invaluable insight into psychological testing and administration. Thanks also to Lee Suckno, M.D., Antony Cifelli, M.D., Traian Parvulescu, M.D., and Daniel DaSilva, Ph.D., for their medical and psychological expertise. Cezar Baula and Chris Buck helped with chemical and pharmaceutical details. Once again, my cousin Greg Tear was both a vital sounding board and a fount of ideas. And ongoing thanks to Special Agent Douglas Margini for his assistance with law enforcement aspects of the book.

A special thanks to Douglas Preston for his support and encouragement throughout the writing of this book, and for supplying a crucial chapter.

I’d also like to thank Bruce Swanson, Mark Mendel, and Jim Jenkins, for their guidance and friendship.

Last, I want to thank those without whom my novels could never exist: my wife, Luchie; my daughter, Veronica; my parents, Bill and Nancy; and my siblings, Doug and Cynthia.

It goes without saying that the characters, corporations, events, locales, entities, pharmaceutical products, psychological apparatus, governmental bodies, computing devices, and the rest of the clay out of which this novel was fashioned are all fictitious, or are used fictitiously. The Eden Incorporated of this book — though it may exist some day — is at present a caprice of my imagination.

It was the first time Maureen Bowman had ever heard the baby cry.

She hadn’t noticed right away. In fact, it had taken five, perhaps ten minutes to register. She’d almost finished with the breakfast dishes when she stopped to listen, suds dripping from her yellow-gloved hands. No mistake: crying, and from the direction of the Thorpe house.

Maureen rinsed the last dish, wrapped the damp towel around it, and turned it over thoughtfully in her hands. Normally, the cry of a baby would go unnoticed in her neighborhood. It was one of those suburban sounds, like the tinkle of the ice cream truck or the bark of a dog, that passed just beneath the radar of conscious perception.

So why had she noticed? She dropped the plate into the drying rack.

Because the Thorpe baby never cried. In the balmy summer days, with the windows thrown wide, she’d often heard it cooing, gurgling, laughing. Sometimes, she’d heard the infant vocalizing to the sounds of classical music, her voice mingling in the breeze with the scent of piñon pines.

Maureen wiped her hands on the towel, folded it carefully, then glanced up from the counter. But it was September now; the first day it really felt like autumn. In the distance, the purple flanks of the San Francisco peaks were wreathed in snow. She could see them, through a window shut tight against the chill.

She shrugged, turned, and walked away from the sink. All babies cried, sooner or later; you’d worry if they didn’t. Besides, it was none of her business; she had plenty of things to take care of without messing in her neighbors’ lives. It was Friday, always the busiest day of the week. Choir rehearsal for herself, ballet for Courtney, karate for Jason. And it was Jason’s birthday; he’d demanded beef fondue and chocolate cake. That meant another trip to the new supermarket on Route 66. With a sigh, Maureen pulled a list from beneath a refrigerator magnet, grabbed a pencil from the phone stand, and began scrawling items.

Then she stopped. With the windows all closed, the Thorpe baby must really be cranking if she could hear…

Maureen forced the thought from her mind. The infant girl had barked her shin or something. Maybe she was becoming colicky, it wasn’t too late for that. In any case, the Thorpes were adults; they could deal with it. The Thorpes could deal with anything.

This last thought had a bitter undertone, and Maureen was quick to remind herself this was unfair. The Thorpes had different interests, ran in different circles; that was all.

Lewis and Lindsay Thorpe had moved to Flagstaff just over a year before. In a neighborhood full of empty nesters and retirees, they stood out as a young, attractive couple, and Maureen had been quick to invite them to dinner. They’d been charming guests, friendly and witty and very polite. The conversation had been easy, unforced. But the invitation had never been returned. Lindsay Thorpe was in her third trimester at the time; Maureen liked to believe that was the reason. And now, with a new baby, back full-time at work… it was all perfectly understandable.

She walked slowly across the kitchen, past the breakfast table, to the sliding glass door. From here, she had a better view of the Thorpes’. They’d been home the night before, she knew; she’d seen Lewis’s car driving past around dinnertime. But now, as she peered out, all seemed quiet.

Except for the baby. God, the little thing had leather lungs…

Maureen stepped closer to the glass, craning her neck. That’s when she saw the Thorpes’ cars. Both of them, twin Audi A8s, the black one Lewis’s and the silver one Lindsay’s, parked in the breezeway.

Both home, on a Friday? This was seriously weird. Maureen pressed her nose up against the glass.

Then she stepped back. Now listen, you’re being exactly the kind of nosy neighbor you promised you’d never be. There could be any number of explanations. The little girl was sick, the parents were home to tend to her. Maybe grandparents were arriving. Or they were getting ready to go on vacation. Or…

The child’s cries had begun to take on a hoarse, ragged quality. And now, without thinking, Maureen put her hand on the glass door and slid it open.

Wait, I can’t just go over there. It’ll be nothing. I’ll embarrass them, make myself look like a fool.

She looked over at the counter. The night before, she’d baked an enormous quantity of tollhouse cookies for Jason’s birthday. She’d bring some of those over; that was a reasonable, neighborly thing to do.

Quickly, she grabbed a paper plate — thought better of it — replaced it with a piece of her good china, arranged a dozen cookies on it, and covered them with plastic wrap. She scooped up the plate, made for the door.

Then she hesitated. Lindsay, she remembered, was a gourmet chef. A few Saturdays before, when they’d met at their mailboxes, the woman had apologized for being unable to chat because she had a burnt-almond ganache boiling on the stove. What would they think of a homely plate of tollhouse cookies?

You’re thinking about this way, way too much. Just go on over there.

What was it, exactly, she found so intimidating about the Thorpes? The fact they didn’t seem to need her friendship? They were well educated, but Maureen had her own cum laude degree in English. They had lots of money, but so did half the neighborhood. Maybe it was how perfect they seemed together, how ideally suited to each other. It was almost uncanny. That one time they’d come over, Maureen had noticed how they unconsciously held hands; how they frequently completed each other’s sentences; how they’d shared countless glances that, though brief, seemed pregnant with meaning. “Disgustingly happy” was how Maureen’s husband termed them, but Maureen didn’t think it disgusting at all. In fact, she’d found herself feeling envious.

Steadying her grip on the plate of cookies, she walked to the door, pulled back the screen, and stepped outside.

It was a beautiful, crisp morning, the smell of cedar strong in the thin air. Birds were piping in the branches overhead, and from down the hill, in the direction of town, she could hear the mournful call of the Southwest Chief as it pulled into the train station.