by Isaac Asimov
“Wouldn’t that work?” Steve asked.
“Not necessarily,” said Hunter. “Assuming that I am on the scene at the same time, the First Law would require me to protect the human from immediate harm as well. I would not be free to act purely on my own judgment.”
“We’ll set up a hoax,” said Jane.
“I like that,” said Steve.
“A hoax?” Hunter asked. “Of what design?”
“Well, I’m not sure. But suppose MC 1 is made to believe that Steve, Chad, and I are in danger. That will free him from Dr. Nystrom’s orders.”
“Yes, clearly,” said Hunter.
“So if you know that the implied danger is false, then the First Law won’t hamper your actions. Right?”
“Correct,” said Hunter.
“So you can pounce on him,” said Steve. “It ought to work, I’d say.”
“What about Dr. Nystrom?” Chad asked. “I guess we don’t want to leave him running around the Late Cretaceous Period, either, do we?”
“No,” said Hunter. “If any of us can apprehend him, we must do so. However, Wayne remains our second priority. His only reason to be here is to control MC 1, so if we return to our time with MC 1, then Wayne will follow. He has no other reason to be here.”
“That’s clear enough,” said Steve.
“What will our hoax be?” Hunter asked. “It must make a great deal of noise and commotion to attract MC 1‘s attention, wherever he is.”
“Wait a minute,” said Jane. “What if he has turned off his hearing again?”
“I believe he no longer has any reason to do that,” said Hunter. “Now he has a human companion and a First Law imperative to protect him from predatory animals. To do that most efficiently, he will need to maintain his auditory sense.”
“The previous question still stands, though,” said Chad. “What will our hoax be?”
“Chad, let’s use dinosaurs,” said Steve.
“How?”
“Can we stampede some of them in the direction of MC 1 and Wayne?”
“Hold it,” said Hunter. “That would put Wayne into genuine danger.”
“Once we get the stampede started, we’ll ride out ahead of it, yelling for help,” said Steve. “You’ll be running with us. If the First Law forces you to intervene, you’ll be right there on hand.”
“Wait a minute,” said Chad. “How can we start a stampede from behind and then ride in front of it?”
“A stampede starts slowly,” said Steve. “Even a predator can be startled and made to run for safety … or at least, in our time they can.”
“Well … I don’t know. I suppose they would react the same way they do in response to a forest fire. Their survival instinct would be triggered by seeing all the animals fleeing in the same direction.”
“I’m sure MC 1 would interpret a dinosaur stampede as a First Law problem,” said Jane, holding back laughter. “I really don’t imagine any robot would have a problem making that particular judgment.”
“Good,” said Steve. “We’ll ride along the stream, where a certain number of dinosaurs are likely to be. We’ll ride fast and yell a lot and get some of them running toward MC 1 and Wayne. Since we know where we’re going, we can ride alongside the rush and get out ahead of them. A forest stampede doesn’t really move at a dead run. It faces too many natural obstacles and too much confusion.”
“I might be able to go along with this,” said Hunter. “Chad, what does our resident paleontologist think?”
“It might be a big mistake.”
“In what way?”
“I barely have control of this struthiomimus as it is. Setting a bunch of dinosaurs in motion, out of control, is just asking for trouble.”
“I understand that this plan has a significant unpredictability,” said Hunter. “So far, I interpret the degree of unpredictability to be acceptable. Do you have other objections?”
“Yeah. We have no idea what species we’ll be dealing with. It’s not just the predators, large and small. Many of the herbivores are gigantic, too, you know. They won’t be fast, relatively speaking, but once they’re on the move, a stampede of elephants will seem downright manageable by comparison.”
Steve laughed. “You still have no sense of adventure. You’re just too sheltered, timid, and intellectual to take action in the real world.”
In the front saddle, Chad turned angrily to look over his shoulder, but Hunter spoke first.
“We will try this plan,” said Hunter. “Since you are all on one mount, I can run beside you and perform my First Law duties if any arise.”
Steve could see Chad shake his head in silence.
“Steve, putting this plan into action strikes me as your area,” said Hunter. “On this project I ask you to give the instructions. What should we do?”
“Make your best guess about the position of MC 1 and Wayne. Then calculate where they may be, roughly, during the next half hour.”
“Then what do we do?”
“Take us back to the stream.”
Hunter nodded. He was unusually quiet, but he changed the direction of their journey through the forest. None of them spoke.
When they reached the stream, Hunter began wading up the middle of the current. It was no more than waist-deep to him at the deepest, and usually more shallow than that. Chad guided the struthiomimus after him.
“This is a good spot,” Chad said quietly.
Hunter stopped and waited for them to ride up next to him. “What do you mean?”
Chad pointed. “We have a lot of herbivores visible here if you look carefully. There’s an anodontosaurus feeding on the left, up ahead. A stegoceras — maybe even the same one we captured — is drinking a little past it. I can see the heads of some hadrosaurs — the duckbill guys — in the distance.”
“Is this a good place to begin the stampede?” Hunter asked.
“I would say so. In a forest this dense, the wildlife we can see at anyone time is only a small fraction of what’s actually present.”
“So if we can see this many, we have a good start,” said Jane. “Okay, now what do we do?”
“Steve, what is your opinion?” Hunter asked.
“I think Chad’s right,” said Steve. “But which way do we chase them? Where is MC 1?”
“That way.” Hunter pointed ahead at an angle to the right of the stream.
“All right,” said Steve. “We’ll start slow and see how they react. Chad, move up slowly. We’ll all start yelling and waving our arms and try to get them moving.”
“All right.” Now that Chad had accepted the proposed action, he was giving it all his attention. “Now!”
The struthiomimus leaped forward and began splashing upstream. Steve yelled and whooped, and Chad and Jane did the same. Hunter tried a variety of noises and finally settled on a rumbling, leonine roar from his versatile larynx.
Small animals in the tree branches responded first, jumping away or fluttering into the air. Steve saw the family of duckbill dinosaurs glance quickly at them and then slip away into the dense forest. The swishing of branches and shaking of large bushes were the only signs that many other animals were starting to move.
“Hyah!” Steve shouted, waving one arm and holding on to his saddle with the other. “Chad, chase’ em! Into the woods!”
Chad reined to the right, and the struthiomimus sprang up the bank, threatening to throw its three riders for a moment. Then they were up into the forest, still yelling and chasing the dinosaurs. Hunter jogged nearby, staying close.
Steve laughed as he shouted, easily the most boisterous of the group. This was the kind of adventure he relished, though certainly even he had never stampeded dinosaurs before. Chad and Jane were clearly enjoying themselves as well.
Ahead of them, more and more dinosaurs were becoming visible as they were startled from their feeding, hunting, or sleeping. The riders followed in a crooked, haphazard path around the trees and bigger bushes. As the momentum of the
chase increased, the stampede grew, the animals always running in roughly the same direction. Soon the forest was filled with the sound of thundering feet and breaking branches.
“That should be plenty,” Steve called.
“Definitely,” Jane shouted over her shoulder. “This will scare the lubricant out of MC 1.”
“Around to the left!” Steve yelled at Chad.
Chad drew on the reins and the struthiomimus responded. They angled left and soon had worked their way over to the left rear of the stampeding dinosaurs. Hunter, of course, kept his pace and position with no trouble.
“Still the right direction?” Steve shouted to Hunter.
“Yes,” he called back.
Now that they were riding off to one side of the stampede, the struthiomimus lost some of its hesitancy and ran even faster on its two long legs. They began moving up on the host of dinosaurs. Steve could see Chad rising half out of the front saddle on his stirrups, gleefully yelling and waving one hand.
Jane, too, looked at Chad and laughed. She even glanced over her shoulder and winked at Steve. Chad had loosened up a lot on this ride.
“Hunter! Do you know where they are?” Steve shouted, as the struthiomimus pranced out to the fore of the stampede, still safely to the left.
“The tracks are fresh,” Hunter called back, now at a faster run to keep up. “No more than a quarter kilometer ahead of us, and not much less.”
“We’d better get well ahead of the rush,” Steve yelled to everyone.
“That’s right,” Jane answered. She turned to speak to Steve over her shoulder, but stopped, staring back at the stampede with widening eyes. “Look!”
Steve looked. Even he recognized the two tall, monstrous fanged dinosaurs that towered over the rest of the stampede in the distant trees. The stampede had flushed out two Tyrannosaurus Hexes, and both of them were running in the humans’ direction.
20
“CHAD!” JANE POUNDED on his shoulder and pointed to the rear of the stampede.
Chad started in shock, but didn’t say anything. Now that the two gigantic carnivores were running in the rear of the stampede, the smaller animals were not going to stop any time soon. Chad pulled on the reins to angle away from the frantic rush they had begun.
“Hunter! See ’em?” Steve yelled.
“Yes. We must find Wayne and MC 1. Stay with me,” Hunter shouted back with robotic calm. “I am now in radio contact with MC 1 about the impending First Law imperative.”
Steve looked back at the stampede. “We don’t have much time to find ’em!”
“There they are!” Chad shouted, pointing ahead.
Steve leaned around Jane to look. MC 1 was struggling through the woods toward Hunter with Wayne on his back, moving faster than a human could run for very long. However, he was going much too slowly to escape the stampede.
As Hunter ran toward them, MC 1 made what progress he could. Obviously, MC 1 had seen that the First Law now required that he use Hunter’s help to save Wayne. Chad guided the struthiomimus in the same direction.
Steve looked back over his shoulder. The stampede had broken up. The smaller dinosaurs were scattering in all directions, trying to flee the tyrannosauruses, making all kinds of different noises as they ran.
The tyrannosauruses were at least five meters tall. Their jaws alone were nearly one meter long and full of dagger-shaped teeth. Tiny forearms with long claws reached out from their massive bodies as they ran on powerful legs.
A triceratops, maybe the one Hunter had told them of finding or maybe another one, had stopped running. It had originally been caught up in the stampede as a general alarm, but it clearly had no fear of a tyrannosaurus. As Steve watched, it simply turned warily to protect itself.
One tyrannosaurus was too close to turn its back. It bellowed in a deep roar and the triceratops charged it, the three horns on its head at the level of the carnivore’s abdomen. The tyrannosaurus dodged to one side and snapped downward with its great jaws.
The two massive dinosaurs turned and shuffled against each other. The triceratops, on its four legs, rammed forward. The tyrannosaurus, tall on its two powerful legs, shifted laterally to get around the heavy frill protecting the neck and back of the triceratops. They trampled all the underbrush and smashed down tree trunks that got in their way.
Chad was just pulling up next to MC 1 and Hunter. “Now what do we do?”
“Hurry,” Jane yelled.
“Unnecessary advice,” Hunter said patiently.
“I can’t believe this,” said Wayne, staring at the dinosaurs racing in all directions behind them.
“Remain calm.” Hunter took Wayne on his own back. “I will save Wayne.” He took off at a run.
Steve leaned down and spoke to MC 1. “You follow us and stay close. Right?”
“Right,” said MC 1.
Jane also turned to the small robot. “After the First Law imperative has passed, you stay with us or join us if we get separated. Ignore all statements from Wayne until we get a chance to talk to you. We have to explain a complex First Law problem that you haven’t had a chance to consider. Acknowledge your agreement under the Second Law.”
“Agreed.”
“Then let’s get of here!” Steve yelled to Chad urgently.
“Look out!” While the triceratops rammed the first tyrannosaurus again, tearing at its insides, the second tyrannosaurus was lumbering through the forest directly toward them, smashing everything in its path underfoot. By now, most of the other dinosaurs had put more distance between themselves and the battling giants. That left the struthiomimus, its riders, and MC 1 as the closest prey it could see.
Chad yanked on the reins and all three human riders kicked their mount. It took off after Hunter, with MC 1 running along behind. Steve stole another look over his shoulder. The tyrannosaurus was crashing toward them, its eyes fixed on him and its rows of teeth gleaming.
“Faster!” Steve yelled, though he realized the struthiomimus could hardly run at top speed while carrying the weight of three humans.
In front of them Hunter was slipping through the bushes with Wayne on his back. Suddenly, as Steve watched, Wayne simply vanished. Steve figured he had activated his version of the device that would take him forward to their own time.
Steve saw Hunter stop to glance behind him, but the robot obviously reached the same conclusion about Wayne. Hunter looked up and waved for the humans to ride past him. Then he leapt into the air, grabbed a tree branch and pulled himself up.
“Go back to the camp!” Hunter shouted at Chad, as the struthiomimus rushed below him. At the same time he was still climbing the tree to get above the head of the tyrannosaurus.
“Right!” Chad shouted back, over his shoulder.
Hunter shifted to radio communication. “MC 1, climb a tree near me. We must work together to distract this dinosaur from pursuing them.”
“Agreed.” Now running just a short distance ahead of the roaring tyrannosaurus, MC 1 also found a low-hanging branch within reach. He grabbed it and quickly scrambled up into a tree next to Hunter’s and climbed to a safe height. “What do you suggest?”
“We will jump on its back,” said Hunter. “Time your jump … now!”
Using his precise vision, timing, and coordination, Hunter leapt onto the back of the tyrannosaurus’s head, his arms and legs spread-eagled to hang on. As he had calculated, he was barely able to slide down to the dinosaur’s neck, which was just narrow enough for him to catch.
Startled, the tyrannosaurus stopped and turned, trying to shake the sudden weight off the back of its neck.
“Prepare for my weight,” MC 1 radioed. In that moment MC 1 dropped from his tree on top of Hunter. Only this time, while Hunter clung to the back of the creature’s neck, MC 1 expertly slid over to one side and down Hunter’s right leg.
The tyrannosaurus was prancing and jerking madly, trying to shake off its two tormentors. Hunter looked down and saw MC 1 deliberately drop down to and gr
ab one of the short forearms of the tyrannosaurus.
Now the tyrannosaurus shook his forearms and clawed at MC 1 with his free hand. He could not, however, bend down close enough to snap at MC 1 with his jaws. The dinosaur’s skeletal structure would not let him reach MC 1.
“I cannot hold this position long,” MC 1 radioed. “He will claw me off in a moment. Do you have further suggestions?”
“Drop to the ground and run for another tree,” Hunter answered. “Watch carefully. If the tyrannosaurus continues to pursue the humans, we must distract it further. Otherwise, stand by for me to join you.”
Hunter saw MC 1 release the tyrannosaurus’s forearm and land on his feet. Then MC 1 avoided the big, shuffling feet of the tyrannosaurus and dived behind a big tree trunk. As the tyrannosaurus bent down, snapping its huge jaws just behind MC 1, Hunter snagged a tree branch in one hand and pulled himself up.
Hunter climbed hand over hand as fast as he could. He drew is legs up to keep them away from the tyrannosaurus. In only a moment he was out of the predator’s reach.
“I am safe,” Hunter radioed. “Acknowledge.”
“Safe,” said MC 1. “When the dinosaur straightened up to snap at you, I was able to climb to safety.”
The tyrannosaurus glared up at Hunter, but knew the robot was out of reach. After a moment, it lumbered away. Hunter watched it go.
“It seems to have forgotten the humans,” said Hunter. “We will watch it a little longer.”
The two robots remained motionless and silent as the big predator gradually wandered away. It was clearly hunting, or at least scavenging, but the robots were of no more interest to it than any other prey. Finally Hunter’s senses indicated that the tyrannosaurus was gone.
“We will move to the ground and join the humans at the camp,” Hunter radioed. “I over heard Steve and Jan, two of the humans, give you Second Law instructions to this effect. Do you have any objection to this?”
“No,” said MC 1. “I am under the Second Law obligation that you observed.”
“Let us go,” said Hunter, as he began to climb down. “Since I do not want to leave the humans without our company any longer than necessary, we will run.