"Yo, we can walk," says the boy, now staring at the puppies on the torn bag. The Digger sees the green figure in the WALK/DON'T WALK light.

The green figure seems happy.

Whatever happy is.

Holding hands, the two of them walk across the street.

The District of Columbia Topographic and Geologic Archives is housed in a musty old building near Seventh and E Streets.

It also, not coincidentally, is located near a little-known Secret Service facility and the National Security Council's Special Operations Office.

There's no reference to the Archives in any tourist literature and visitors who notice the sign on the front of the building and walk inside are politely told by one of the three armed guards at the front desk that the facility is not open to the public and that there are no exhibitions here but thank you for your interest. Have a nice day. Goodbye.

Cage, Parker and Lukas-on her ever-present phone-waited in the lobby. She shut off the unit. "Nothing. He just disappeared."

"No witnesses?"

"A couple of drivers saw a man in dark clothes running. They think he was white. They think he was medium build. But nobody'd swear to it. Jesus."

Cage looked around. "How'd you get us in here, Lukas? I couldn't get us in here."

Now it was Lukas's turn to shrug cryptically. It seemed that New Year's Eve was the day to call in markers and incur debts.

They were joined by Tobe Geller, who entered the facility at a slow trot. He nodded a greeting to the other members of the team. Then their fingerprints were checked by an Identi-Scanner and their weapons secured in a lock box. They were all directed to an elevator. They stepped into the car. Parker expected to rise but this elevator, it seemed, went no higher than the first floor. Lukas hit the button marked B7 and the car descended for what seemed like forever.

They stepped out into the Archives proper. Which turned out not to be stacks of dusty, old books and maps-which Parker, Certified Document Examiner, had been looking forward to checking out-but a huge room filled with high-tech desks, telephones, microphones and banks of twenty-four-inch NEC computer screens. Even tonight, New Years Eve, two dozen men and women sat in front of these screens, on which glowed elaborate maps, typing on keyboards and speaking into stalk mikes.

Where the hell am I? Parker wondered, looking around and concluding that the issue of access to the Archives had nothing to do with finding a civil servant with a key to the front door.

"What is this?" he asked Geller.

The young agent glanced tactfully at Cage, who nodded his okay to tell all. Geller replied, "Topographic and cartographic database of two hundred square miles around the District. Ground zeros the White House though they don't like it when you say that. In case of natural disaster, terrorist attack, nuclear threat-whatever-this's where they figure out if it's best for the government to sit tight or get out of town and if so how they ought to do it. What routes are safest, how many congressmen'll survive, how many senators. That sort of thing. Like the war room in Fail Safe. Way cool, hmm?"

"What're we doing here?"

"You wanted maps," he said, looking excitedly at all the equipment the way only a born hacker would do, "and this's the most comprehensive physical database of any area in the world. Lincoln Rhyme was saying we needed to know the area. Well, we may not. But they do." He nodded affectionately toward a long row of six-foot-high computer towers.

Lukas said, "They're letting us use the facility, under protest, provided we don't take any printouts or downloads with us."

"We get searched on the way out," Geller said.

"How come you know so much about it?" Parker asked Geller.

"Oh, I sort of helped set it up."

Lukas added, "Oh, by the way, Parker, you've never heard of this place."

"Not a problem," said Parker, eyeing the two machine-gun-armed guards by the elevator door.

Lukas said, "Now, what're the materials Rhyme found?"

Parker looked at the notes he'd taken. He read, "Granite, sulfur, soot, ash, clay and brick."

Tobe Geller sat down at a monitor, turned it on, typed madly on a keyboard. An image of the Washington, D.C., area came on the screen. The resolution was astonishing. It looked three-dimensional. Parker thought, absurdly, how Robby and Stephie would love to play Mario Bros. on a monitor like this.

Lukas said to Parker, "Where do we start?"

"One clue at a time," he responded. "Then start narrowing down possibilities. The way you solve puzzles."

Three hawks have been killing a farmer's chickens…

"First, granite, brick dust and clay," he mused. "They point to demolition sites, construction…" He turned to Geller. "Would they be on this database?"

"No," the young agent responded. "But we can track down somebody at Building Permits."

"Do it," Parker ordered.

Geller made the call on a landline-no cell phone would work this far underground and, besides, like all secure facilities in Washington, Parker supposed, the walls were shielded.

"What next?" Parker wondered. "Sulfur and soot… That tells us it's industrial. Tobe, can you highlight areas based on air pollutants?"

"Sure. There's an EPA file." He added cheerfully, "Its to calculate penetration levels of nerve gas and bioagent weapons."

More buttons.

The business of the District of Columbia is government, not industry, and the commercial neighborhoods were devoted mostly to product warehousing and distribution. But on the screen portions of the city began to be highlighted-in, appropriately, pollution-tinted yellow. The majority were in the Southeast part of town.

"He's probably living near there," Lukas reminded. "What industrial sites are adjacent to areas of houses and apartments?"

Geller continued to type, cross-referencing the industrial neighborhoods with residential. This eliminated some but not many of the manufacturing areas; most of them were ringed with residential pockets.

"Still too many," Lukas said.

"Let's add another clue. The ash," Parker said. "Basically burnt animal flesh."

Geller's hands paused above the keyboard. He mused, "What could that be?"

Lukas shook her head. Then asked, "Are there any meat-processing plants in any of those areas?"

This was a good suggestion, one Parker himself had been about to make.

Geller responded, "None listed."

"Restaurants?" Cage suggested.

"Probably too many of them," Parker said.

"Hundreds," Geller confirmed.

"Where else would there be burnt meat?" Lukas asked no one in particular.

Puzzles…

"Veterinarians," Parker wondered. "Do they dispose of the remains of animals?"

"Probably," Cage said.

Geller typed then read the screen. "There are dozens. All over the place."

Then Lukas looked up at Parker and he saw that the chill from earlier was gone, replaced by something else. It might have been excitement. Her blue eyes were stones still, perhaps, but now they were radiant gems. She said, "How about human remains?"

"A crematorium!" Parker said. "Yes! And the polished granite-that could be from tombstones. Let's look for a cemetery."

Cage gazed at the map. He pointed. "Arlington?"

The National Cemetery took up a huge area on the west side of the Potomac. The area around it must be saturated with granite dust.

But Parker pointed out: "Its not near any industrial sites. Nothing with significant pollution."

Then Lukas saw it. "There!" She pointed a finger, tipped with an unpolished but perfectly filed nail. "Gravesend."