"I know I saw a raptor," Tim said.

"I'm hungry," Lex said. She was starting to whine.

In the control room, Arnold turned to Wu. "What do you think the kid saw?"

"I think it must have been an otby."

Arnold nodded. "We have trouble tracking otbys, because they spend so much time In the trees." The otbys were an exception to the usual minute-to-minute control they maintained over the animals. The computers were constantly losing and picking up the othys, as they went into the trees and then came down again.

"What burns me," Hammond said, "is that we have made this wonderful park, this fantastic park, and our very first visitors are going through it like accountants, just looking for problems. They aren't experiencing the wonder of it at all."

"That's their problem," Arnold said. "We can't make them experience wonder." The intercom clicked, and Arnold heard a voice drawl, "Ah, John, this is the Anne B over at the dock. We haven't finished offloading, but I'm looking at that storm pattern south of us. I'd rather not be tied up here if this chop gets any worse."

Arnold turned to the monitor showing the cargo vessel, which was moored at the dock on the east side of the island. He pressed the radio button. "How much left to do, Jim?"

"Just the three final equipment containers. I haven't checked the mainfest, but I assume you can wait another two weeks for it. We're not well berthed here, you know, and we are one hundred miles offshore."

"You requesting permission to leave?"

"Yes, John."

"I want that equipment," Hammond said. "That's equipment for the labs. We need it."

"Yes," Arnold said. "But you didn't want to put money into a storm barrier to protect the pier. So we don't have a good harbor. If the storm gets worse, the ship will be pounded against the dock. I've seen ships lost that way. Then you've got all the other expenses, replacement of the vessel plus salvage to clear your dock… and you can't use your dock until you do…"

Hammond gave a dismissing wave. "Get them out of there."

"Permission to leave, Anne B, " Arnold said, into the radio.

"See you in two weeks," the voice said.

On the video monitor, they saw the crew on the decks, casting off the lines. Arnold turned back to the main console bank. He saw the Land Cruisers moving through fields of steam.

"Where are they now?" Hammond said.

"It looks like the south fields," Arnold said. The southern end of the island had more volcanic activity than the north. "That means they should be almost to the stegos. I'm sure they'll stop and see what Harding is doing."

As the Land Cruiser came to a stop, Ellie Sattler stared through the plumes of steam at the stegosaurus. It was standing quietly, not moving. A Jeep with a red stripe was parked alongside it.

"I have to admit, that's a funny-looking animal," Malcolm said.

The stegosaurus was twenty feet long, with a huge bulky body and vertical armor plates along its back. The tail had dangerous-looking three-foot spikes. But the neck tapered to an absurdly small head with a stupid gaze, like a very dumb horse.

As they watched, a man walked around from behind the animal. "That's our vet, Dr. Harding," Regis said, over the radio. "He's anesthetized the stego, which is why it's not moving. It's sick."

Grant was already getting out of the car, hurrying toward the motionless stegosaur. Ellie got out and looked back as the second Land Cruiser pulled up and the two kids jumped out. "What's he sick with?" Tim said.

"They're not sure," Ellie said.

The great leathery plates along the stegosaur's spine drooped slightly. It breathed slowly, laboriously, making a wet sound with each breath.

"Is it contagious?" Lex said.

They walked toward the tiny head of the animal, where Grant and the vet were on their knees, peering into the stegosaur's mouth.

Lex wrinkled her nose. "This thing sure is big," she said. "And smelly."

"Yes, it is." Ellie had already noticed the stegosaur had a peculiar odor, like rotting fish. It reminded her of something she knew, but couldn't quite place. In any case, she had never smelled a stegosaur before. Maybe this was its characteristic odor. But she had her doubts. Most herbivores did not have a strong smell. Nor did their droppings. It was reserved for the meat-eaters to develop a real stink.

"Is that because it's sick?" Lex asked.

"Maybe. And don't forget the vet's tranquilized it."

"Ellie, have a look at this tongue," Grant said.

The dark purple tongue drooped limply from the animal's mouth. The vet shone a light on it so she could see the very fine silvery blisters. "Microvesicles," Ellie said. "Interesting."

"We've had a difficult time with these stegos," the vet said. "They're always getting sick."

"What are the symptoms?" Ellie asked. She scratched the tongue with her fingernail. A clear liquid exuded from the broken blisters.

"Ugh," Lex said,

"Imbalance, disorientation, labored breathing, and massive diarrhea," Harding said. "Seems to happen about once every six weeks or so."

"They feed continuously?"

"Oh yes," Harding said. "Animal this size has to take in a minimum of five or six hundred pounds of plant matter daily just to keep going. They're constant foragers."

"Then it's not likely to be poisoning from a plant," Ellie said. Constant browsers would be constantly sick if they were eating a toxic plant. Not every six weeks.

"Exactly," the vet said.

"May I?" Ellie asked. She took the flashlight from the vet. "You have pupillary effects from the tranquilizer?" she said, shining the light in the stegosaur's eye.

"Yes. There's a miotic effect, pupils are constricted."

"But these pupils are dilated," she said.

Harding looked. There was no question: the stegosaur's pupil was dilated, and did not contract when light shone on it. "I'll be damned," he said. "That's a pharmacological effect."

"Yes." Ellie got back on her feet and looked around. "What is the animal's range?"

"About five square miles."

"In this general area?" she asked. They were in an open meadow, with scattered rocky outcrops, and intermittent plumes of steam rising from the ground. It was late afternoon, and the sky was pink beneath the lowering gray clouds.

"Their range is mostly north and cast of here," Harding said. "But when they get sick, they're usually somewhere around this particular area."

It was an interesting puzzle, she thought. How to explain the periodicity of the poisoning? She pointed across the field. "You see those low, delicate-looking bushes?"

"West Indian lilac." Harding nodded. "We know it's toxic. The animals don't eat it."

"You're sure?"

"Yes. We monitor them on video, and I've checked droppings just to be certain. The stegos never eat the lilac bushes."

Melia azedarach, called chinaberry or West Indian lilac, contained a number of toxic alkaloids. The Chinese used the plant as a fish poison.

"They don't eat it," the vet said.

"Interesting," Ellie said. "Because otherwise I would have said that this animal shows all the classic signs of Melia toxicity: stupor, blistering of the mucous membranes, and pupillary dilatation." She set off toward the field to examine the plants more closely, her body bent over the ground. "You're right," she said. "Plants are healthy, no sign of being eaten. None at all."

"And there's the six-week interval," the vet reminded her.

"The stegosaurs come here how often?"

"About once a week," he said. "Stegos make a slow loop through their home-range territory, feeding as they go. They complete the loop in about a week."

"But they're only sick once every six weeks."

"Correct," Harding said.

"This is boring," Lex said.

"Ssshb," Tim said. "Dr. Sattler's trying to think."

"Unsuccessfully," Ellie said, walking farther out into the field.

Behind her, she heard Lex saying, "Anybody want to play a little pickle?"

Ellie stared at the ground. The field was rocky in many places. She could hear the sound of the surf, somewhere to the left. There were berries among the rocks. Perhaps the animals were just eating berries. But that didn't make sense. West Indian lilac berries were terribly bitter.

"Finding anything?" Grant said, coming up to join her.

Ellie sighed. "Just rocks," she said. "We must be near the beach, because all these rocks are smooth. And they're in funny little piles."

"Funny little piles?" Grant said.

"All over. There's one pile right there." She pointed.

As soon as she did, she realized what she was looking at. The rocks were worn, but it had nothing to do with the ocean. These rocks were heaped in small piles, almost as if they had been thrown down that way.

They were piles of gizzard stones.

Many birds and crocodiles swallowed small stones, which collected in a muscular pouch in the digestive tract, called the gizzard. Squeezed by the muscles of the gizzard, the stones helped crush tough plant food before it reached the stomach, and thus aided digestion. Some scientists thought dinosaurs also had gizzard stones. For one thing, dinosaur teeth were too small, and too little worn, to have been used for chewing food. It was presumed that dinosaurs swallowed their food whole and let the gizzard stones break down the plant fibers. And some skeletons had been found with an associated pile of small stones in the abdominal area. But it had never been verified, and-

"Gizzard stones," Grant said.

"I think so, yes. They swallow these stones, and after a few weeks the stones are worn smooth, so they regurgitate them, leaving this little pile, and swallow fresh stones. And when they do, they swallow berries as well. And get sick."

"I'll be damned," Grant said. "I'm sure you're right."

He looked at the pile of stones, brushing through them with his band, following the instinct of a paleontologist.