Muldoon had taken down the launcher, and was loading the second canister.

"You hit him?" Gennaro said.

Muldoon shook his head. "Missed. Damn laser sights… See if there's a battery in the case."

"A what?" Gennaro said.

"A battery," Muldoon said. "It's about as big as your finger. Gray markings."

Gennaro bent over to look in the steel case. He felt the vibration of the Jeep, heard the motor ticking over. He didn't see a battery. The tyrannosaur roared. To Gennaro it was a terrifying sound, rumbling from the great chest cavity of the animal, bellowing out over the landscape. He sat up sharply and reached for the steering wheel, put his hand on the gearshift. On the radio, he heard a voice say, "Muldoon. This is Arnold. Get out of there. Over."

"I know what I'm doing," Muldoon said.

The tyrannosaur charged.

Muldoon stood his ground. Despite the creature racing toward him, he slowly and methodically raised his launcher, aimed, and fired. Once again, Gennaro saw the puff of smoke, and the white streak of the canister going toward the animal.

Nothing happened. The tyrannosaur continued to charge.

Now Muldoon was on his feet and running, shouting, "Go! Go!" Gennaro put the Jeep in gear and Muldoon threw himself onto the side door as the Jeep lurched forward. The tyrannosaur was closing rapidly, and Muldoon swung the door open and climbed inside.

"Go, damn it! Go!"

Gennaro floored it. The Jeep bounced precariously, the front end nosing so high they saw only sky through the windshield, then slamming down again toward the ground and racing forward again. Gennaro headed for a stand of trees to the left until, in the rearview mirror, he saw the tyrannosaur give a final roar and turn away.

Gennaro slowed the car. "Jesus."

Muldoon was shaking his head. "I could have sworn I hit him the second time."

"I'd say you missed," Gennaro said.

"Needle must have broken off before the plunger injected."

"Admit it, you missed."

"Yeah," Muldoon said. He sighed. "I missed. Battery was dead in the damned laser sights. My fault. I should have checked it, after it was out all last night. Let's go back and get more canisters."

The Jeep headed north, toward the hotel. Muldoon picked up the radio. "Control."

"Yes," Arnold said.

"We're heading back to base."

The river was now very narrow, and flowing swiftly. The raft was going faster all the time. It was starting to feel like an amusement park ride.

"Whee!" Lex yelled, holding on to the gunwale. "Faster, faster!"

Grant squinted, looking forward. The river was still narrow and dark, but farther ahead he could see the trees ended, and there was bright sunlight beyond, and a distant roaring sound. The river seemed to end abruptly in a peculiar flat line…

The raft was going still faster, rushing forward.

Grant grabbed for his paddles.

"What is it?"

"It's a waterfall," Grant said.

The raft swept out of the overhanging darkness into brilliant morning sunlight, and raced forward on the swift current toward the lip of the waterfall. The roar was loud in their ears. Grant paddled as strongly as he could, but he only succeeded in spinning the boat in circles. It continued inexorably toward the lip.

Lex leaned toward him. "I can't swim!" Grant saw that she did not have her life vest clasped, but there was nothing he could do about it; with frightening speed, they came to the edge, and the roar of the waterfall seemed to fill the world. Grant jammed his oar deep into the water, it catch and hold, right at the lip; the rubber raft shuddered in the current, but they did not go over. Grant strained against the oar and, looking over the edge, saw the sheer drop of fifty feet down to the surging pool below.

And standing in the surging pool, waiting for them, was the tyrannosaur.

Lex was screaming in panic, and then the boat spun, and the rear end dropped away, spilling them out into air and roaring water, and they fell sickeningly. Grant flailed his arms in the air, and the world went suddenly silent and slow.

It seemed to him he fell for long minutes; he had time to observe Lex, clutching her orange jacket, falling alongside him; he had time to observe Tim, looking down at the bottom; he had time to observe the frozen white sheet of the waterfall; he had time to observe the bubbling pool beneath him as he fell slowly, silently toward it.

Then, with a stinging slap, Grant plunged into cold water, surrounded by white boiling bubbles. He tumbled and spun and glimpsed the leg of the tyrannosaur as he was swirled past it, swept down through the pool and out into the stream beyond. Grant swam for the shore, clutched warm rocks, slipped off, caught a branch, and finally pulled himself out of the main current. Gasping, he dragged himself on his belly onto the rocks, and looked at the river just in time to see the brown rubber raft tumble past him. Then he saw Tim, battling the current, and he reached out and pulled him, coughing and shivering, onto the shore beside him.

Grant turned back to the waterfall, and saw the tyrannosaur plunge its head straight down into the water of the pool at his feet. The great head shook, splashing water to either side. It had something between its teeth.

And then the tyrannosaur lifted its head back up. Dangling from the jaws was Lex's orange life vest.

A moment later, Lex bobbed to the surface beside the dinosaur's long tail. She lay face down in the water, her little body swept downstream by the current. Grant plunged into the water after her, was again immersed in the churning torrent. A moment later, he pulled her up onto the rocks, a heavy, lifeless weight. Her face was gray. Water poured from her mouth.

Grant bent over her to give her mouth-to-mouth but she coughed. Then she vomited yellow-green liquid and coughed again. Her eyelids fluttered. "Hi," she said. She smiled weakly. "We did it."

Tim started to cry. She coughed again. "Will you stop it? What're you crying for?"

"Because."

"We were worried about you," Grant said. Small flecks of white were drifting down the river. The tyrannosaur was tearing up the life vest. Still turned away from them, facing the waterfall. But at any minute the animal might turn and see them… Come on, kids," he said.

"Where are we going?" Lex said, coughing.

"Come on." He was looking for a hiding place. Downstream he saw only an open grassy plain, affording no protection. Upstream was the dinosaur. Then Grant saw a dirt path by the river. It seemed to lead up toward the waterfall.

And in the dirt he saw the clear imprint of a man's shoe. Leading up the path.

The tyrannosaur finally turned around, growling and looking out toward the grassy plain. It seemed to have figured out that they had gotten away.

It was looking for them downstream. Grant and the kids ducked among the big ferns that lined the riverbanks. Cautiously, he led them upstream. "Where are we going?" Lex said. "We're going back."

"I know."

They were closer to the waterfall now, the roar much louder. The rocks became slippery, the path muddy. There was a constant hanging mist. It was like moving through a cloud. The path seemed to lead right into the rushing water, but as they came closer, they saw that it actually went behind the waterfall.

The tyrannosaur was still looking downstream, its back turned to them. They hurried along the path to the waterfall, and had almost moved behind the sheet of falling water when Grant saw the tyrannosaur turn. Then they were completely behind the waterfall, and Grant was unable to see out through the silver sheet.

Grant looked around in surprise. There was a little recess here, hardly larger than a closet, and filled with machinery: humming pumps and big filters and pipes. Everything was wet, and cold.

"Did he see us?" Lex said. She had to shout over the noise of the falling water. "Where are we? What is this place? Did he see us?"

"Just a minute," Grant said. He was looking at the equipment. This was clearly park machinery. And there must be electricity to run it, so perhaps there was also a telephone for communication. He poked among the filters and pipes.

"What are you doing?" Lex shouted.

"Looking for a telephone." It was now nearly 10:00 a.m. They had just a little more than an hour to contact the ship before it reached the mainland.

In the back of the recess he found a metal door marked MAINT 04, but it was firmly locked. Next to it was a slot for a security card. Alongside the door he saw a row of metal boxes. He opened the boxes one after another, but they contained only switches and timers. No telephone. And nothing to open the door.

He almost missed the box to the left of the door. On opening it, he found a nine-button keypad, covered with spots of green mold. But it looked as if it was a way to open the door, and he had the feeling that on the other side of that door was a phone. Scratched in the metal of the box was the number 1023. He punched it in.

With a hiss, the door came open. Gaping darkness beyond, concrete steps leading downward. On the back wall he saw stenciled MAINT VEHICLE 04/22 CHARGER and an arrow pointing down the stairs. Could it really mean there was a car? "Come on, kids."

"Forget it," Lex said. "I'm not going in there."

"Come on, Lex," Tim said.

"Forget it," Lex said. "There's no lights or anything. I'm not going."

"Never mind," Grant said. There wasn't time to argue. "Stay here, and I'll be right back."

"Where're you going?" Lex said, suddenly alarmed.

Grant stepped through the door. It gave an electronic beep, and snapped shut behind him, on a spring.

Grant was plunged into total darkness. After a moment of surprise, he turned to the door and felt its damp surface. There was no knob, no latch. He turned to the walls on either side of the door, feeling for a switch, a control box, anything at all…

There was nothing.

He was fighting panic when his fingers closed over a cold metal cylinder. He ran his hands over a swelling edge, a flat surface… a flashlight! He clicked it on, and the beam was surprisingly bright. He looked back at the door, but saw that it would not open. He would have to wait for the kids to unlock it. Meantime…