"How long?" Josh's knuckles were white on the back of his chair. Very faintly, in the distance, he heard sirens. He ignored them.

"It's been three hours. They went outside to sled after lunch. Their agents watched from a distance, as usual. They all reported the children taking their last run together and going into the house at 12:51 through the side entrance."

"The shed?"

"Yes. Mrs. Moss and Mrs. Lyman Senior were in the living room; they heard the children come in. Or at least, they heard Sally calling to Noah to hurry up and come in, and then heard feet running, the dog barking, laughter."

"Gressie was with them?"

"Yes."

"How was she barking?"

"Playfully, Mrs. Moss said. Nothing to suggest a cause for alarm. The agent by the front door heard it as well, and said he thought the children and the dog were chasing each other through the house."

"And Donna?"

"Was upstairs in your bedroom, wrapping gifts, with the door closed. She says she thought she heard the children and the dog run upstairs. They were making a lot of noise. Then things quieted down. She thought they were playing a game together in Sally's room. She didn't go to check on them."

"Of course not." Josh made an impatient gesture. He wasn't going down that road; whatever had happened-and he still could not allow himself to think that anything had happened-it was not Donna's fault. "She was busy. They were safe inside. Only-they weren't."

"Sally's safe and fine, sir."

"What does she say happened?"

"That Noah was behind her. She didn't see him come into the house. She ran in from the shed through the side door into the kitchen, then upstairs to her room. She was there the rest of the afternoon, playing by herself."

"So all that noise was just Sally and the dog?"

"Yes, sir."

"When did she last see him?"

"She says outside, before she went into the kitchen.

Josh took a deep breath to steady his voice.

"So-where is Noah?"

"We don't know sir. There's no evidence at all of any kind of invasion. The outer perimeter was secured. There'd been a fresh fall of snow in the night; there are no tracks inside the perimeter fence except the agents'."

"What about the interior fence?"

Ron shook his head. "There's no sign of a breach. And no footprints anywhere near that fence, either, except the agents'."

The property Josh and Donna had bought nine years before had included 25 acres of land. They'd added to that from time to time as adjoining acreage came up for sale, so they now owned a considerable parcel of land that extended along the waterfront on either side of the promontory the lighthouse was built on, and back to the road, which was about a mile and a half from the lighthouse and the adjoining keeper's house where the family stayed when they were in residence. The Secret Service had built an exterior perimeter fence around the entire property, and manned it at regular intervals to ensure security. But there was another, lower, fence around the edge of the promontory, that Josh and Donna had put in themselves when Noah was small, to keep him from toddling over the top of the cliff.

An intruder or intruders could, in theory, climb into the compound over that fence, but they would have to climb the cliff first. And before doing that, they'd have to breach the Secret Service's security line at the edges of the property and the base of the cliff. Anyone attempting to reach the property by boat would be stopped by the Secret Service's marine unit or the Coast Guard while they were still well out from shore. Even supposing someone managed to get through those layers of security, they'd still be seen by the agents who patrolled the inner fence along the top of the cliff, or the ones with the surveillance equipment and the snipers' rifles at the top of the tower.

The lighthouse was supposed to be impregnable. It was, after all, the vacation home of the President of the United States.

"You've searched thoroughly? He couldn't be hiding anywhere?"

"We've searched everywhere, sir. The house. The lighthouse tower. The Service buildings behind the crest. Noah's footprints are all over the field behind the house, and down in the dip behind the crest, too-they were sledding in both directions this morning. They go right up to the edge of the Service buildings, along with Sally's and the dog's. But there's no indication he went anywhere else at all."

"Are you sure he couldn't have gone-" Josh took a deep breath, and moistened his lips. His mouth was as dry as sandpaper. "-Over the cliff?"

"His agents were watching the whole time."

"Well, where the hell is my son, then? God damn it, I thought you people had made changes after-" Josh couldn't get Zoey's name out. "I thought you knew what you were doing!"

Ron blinked. His Adam's apple bobbed in his throat. Josh wiped his hand across his forehead and through his hair.

"I'm sorry," he said quietly, after a moment. "I didn't mean that, Ron. I'm sorry."

"That's all right, sir. I understand."

"I thought you could track them?"

Ron sighed.

"You know the tracking devices are removable."

Josh nodded, his mouth suddenly too dry to speak. The children had been microchipped years ago, but that wouldn't make much difference now. As Ron had pointed out in their initial security briefing, no one kidnapping a Presidential child would be interested in disguising their identity. The Service used electronic transmitters to track the whereabouts of their protectees, but they weren't implanted-you had to be able to change the batteries, and anyway, a successful kidnapper would presumably have no difficulty locating an implanted tracking device, and no scruples about ripping it out of a child's skin. The children's devices were in their watches, new ones that they'd helped pick out so they wouldn't object to wearing them.

"One of my men found Noah's watch in the shed, under the edge of the woodpile."

Josh's mouth was a fine white line.

"And now?"

"I'm afraid we have to consider the possibility that one of my agents-"

The two men's eyes locked. Josh nodded slowly. Somehow he managed to loosen his jaw enough to grind out the question, "How will you find out?"

"I'm flying up there now to take over the investigation myself."

"You can come with me on Air Force One."

"No, sir. You can't go. If I've got a turncoat up there, it's too great a security risk."

To be cont'd. . . .