He hunched over the letter, eagerly, the way a jeweler appraises a beautiful yellow stone, ready to declare it false if that's how he saw it but secretly hoping that it will turn out to be rare topaz.

"What's that?" Robby asked, standing and looking at the letter.

"It's what came in the truck yesterday," Parker said, squinting as he checked out an uppercase K, which can be written a number of different ways and therefore is very useful in handwriting analysis.

"Oh, the armored car. That was neat."

It was neat. But it didn't answer the boy's question. Parker continued. "You know Thomas Jefferson?"

"Third president. Oh, and he lived in Virginia. Like us."

"Good. This's a letter that somebody thinks he wrote. They want me to check it and make sure."

One of the more difficult conversations he'd had with Robby and Stephie was explaining what he did for a living. Not the technical part of being a questioned document examiner. But that people would forge letters and documents and try to claim they were real.

"What's it say?" the boy asked.

Parker didn't answer right away. Oh, answers were important to him. He was, after all, a puzzle master-his lifelong hobby was riddles and word games and brain-teasers. He believed in answers and he tried never to defer responding to his children's questions. When a mother or father said, "Later," it was usually for their convenience, hoping the child would forget the question. But the content of this letter made him hedge. After a moment he said, "It's a letter Jefferson wrote to his oldest daughter." This much was true. But Parker didn't go on and tell the boy that the subject of the letter was Mary-his second daughter-who had died of complications from childbirth, as had Jefferson 's wife some years before. He read:

Back here in Washington I live under a sorrowful pall, haunted as I am by visions of Polly on horseback and running along the porch in good-natured defiance of my prescriptions to her to exercise more caution…

Parker, certified document examiner, struggled to ignore the sadness he felt reading those words. Concentrate, he told himself, though the terrible image of a father being deprived of one of his children kept intruding.

A sorrowful pall…

Concentrate.

He observed that the girls nickname in the letter was what Jefferson would have used-born "Mary," the girl was called "Polly" by her family-and that the punctuation-sparse style was typically Jeffersonian. These attested to authenticity. So did some of the events that the letter referred to; they had in fact occurred in Jefferson 's life and had done so around the time the letter had purportedly been written.

Yes, textually at least, the letter seemed real.

But that was only half the game. Document examiners are not only linguists and historians, they are scientists too. Parker still had to perform the physical examination of the letter.

As he was about to slip it under one of his Bausch & Lomb compound microscopes the doorbell rang again.

Oh, no… Parker closed his eyes. It was Joan. He knew it. She'd picked up her dogs and returned to complicate his life further. Maybe she had the social worker with her now. A surprise commando raid…

"I'll get it," Robby said.

"No," Parker said quickly. Too quickly. The boy was unnerved by his abrupt reaction.

Father smiled at son. "I'll go." And slid off the stool, climbed the stairs.

He was mad now. He was determined that the Whos would have a fun New Year's Eve, despite their mother. He flung the door open.

Well…

"Hello, Parker."

It took him a second to remember the name of the tall, gray-haired man. He hadn't seen the agent for years. Then he recalled. "Cage."

He didn't recognize the woman standing beside him.

"How you doin', Parker? Never expected to see me in a month of blue Mondays, did you? Wait, I'm mixing up my expressions. But you get the picture."

The agent had changed very little. A bit grayer. A little more gaunt. He seemed taller. Parker remembered that Cage was exactly fifteen years older than he. They shared June as a birth month. Gemini. Yin-yang.

From the corner of his eye Parker saw Robby appear in the hallway with his coconspirator, Stephie. Word of visitors spreads fast in a household of children. They edged closer to the door, gazing out at Cage and the woman.

Parker turned and bent down. "Don't you two have something to do up in your rooms? Something very important?"

"No," Stephie said.

"Uh-uh," Robby confirmed.

"Well, I think you do."

"What?"

"How many Legos are on the floor? How many Micro Machines?"

"A couple," Robby tried.

"A couple of hundred?"

"Well," the boy said, grinning.

"Upstairs now… Up, up, or the monster'll take you up there himself. Do you want the monster? Do you?"

"No!" Stephie shrieked.

"Go on," Parker said, laughing. "Let Daddy talk to his friend here."

As they started up the stairs Cage said, "Oh, not hardly a friend. Right, Parker?"

He didn't respond. He closed the door behind him and turned back, appraising the woman. She was in her thirties, with a narrow, smooth face. Pale, nothing like Joan's relentless tan. She wasn't looking at Parker but was watching Robby climb the stairs through the lace-curtained window beside the door. She then turned her attention to him and reached out a strong hand with long fingers. She shook his hand firmly. "I'm Margaret Lukas. ASAC at the Washington field office."

Parker recalled that within the Bureau assistant special agents in charge were referred to by the acronym, pronounced A-sack, while the heads of the offices were called S-A-C's. An aspect of his former life he hadn't thought about for years.

She continued, "Could we come inside for a minute?"

A parental warning alarm went off. He responded, "You mind if we stay out here? The children…"

Her eyes flickered and he wondered if she considered this a snub. But that was just too bad; the kids' exposure to the Bureau was limited to sneaking a look at Scully and Mulder on The X-Files when sleeping over at friends' houses. He planned on keeping it that way.

"Fine with us," Cage said for both of them. "Hey, last time I saw you… man, it was a while ago. We were at Jimmy's, you know, his thing on Ninth Street."

"That's right."

It was in fact the last time Parker Kincaid had been at the Bureau headquarters. Standing in the large courtyard surrounded by the somber stone building. A hot July day two years ago. He still got occasional e-mails about what a fine speech he'd delivered at the memorial service for the Jim Huang, who was one of Parker's former assistants. He'd been gunned down on his first day as a field agent.

Parker remained silent.

Cage nodded after the kids. "They're growing."

"They do that," Parker answered. "What exactly is it, Cage?"

The agent gave a shrug toward Lukas.

"We need your help, Mr. Kincaid," she said quickly, before the stream of breath accompanying Parker's question evaporated.

Parker tilted his head.

"It's nice out here," Cage said, looking up. "Fresh air. Linda and I should move. Get some land. Maybe Loudon County. You watch the news, Parker?"

"I listen."

"Huh?"

"Radio. I don't watch TV."

"That's right. You never did." Cage said to Lukas, "'Wasteland,' he'd call TV. He read a lot. Words're Parker's domain. His bailiwick, whatever the hell a bailiwick is. You told me your daughter reads like crazy. She still do that?"

"The guy in the subway," Parker said. "That's what you're here about."

"METSHOOT," Lukas said. "That's what we've acronymed it. He killed twenty-three people. Wounded thirty-seven. Six children were badly injured. There was a-"