Derec was hobbling painfully, slowed to a walk, as Ariel finally dragged him to her destination. It was a depot of the vacuum tube cargo transportation system. He stopped when he saw it, pulling back on her arm.
"Wait a minute," he said. "They had humanoid robots staffing these depots. They"ll report where we"ve gone."
"Not if no one asks. Come on." She pulled harder than he had, and he allowed himself to follow.
As they came up on the loading dock, he saw that he was wrong. A small function robot was alone here now, loading cargo without supervision.
"What if it doesn"t let us get in?" He asked.
"Ignore it." Ariel pushed a small container aside, out of the reach of the function robot"s extended pincers.
The robot itself was a small ovoid shape with six tentacles ending in various gripping tools. Without a positronic brain, it would not interfere deliberately, or respond to the Laws of Robotics, either. As it rolled forward after the small box, Ariel climbed into the open, transparent capsule and reached out to help Derec climb in.
Reluctantly, he stepped over the side of the capsule, in extreme pain, and slowly stretched out inside it.
"We have to go somewhere," he said. "This thing doesn"t have a console inside it. It has to be programmed on the dock console, over there." He pointed.
Ariel hesitated while the function robot placed the small box inside the capsule between her feet and Derec"s head. She squatted down quickly and stretched out just as the function robot closed the trapdoor.
"We"re going wherever this box is," she said. "The good thing is, we haven"t left any kind of trail. That programming is completely independent of us. "
"Yeah-"
His comment was cut short by the sudden acceleration of the capsule. It moved forward on rollers to push through a door that gave under the pressure. Then they were in the vacuum tube itself, and the capsule really picked up speed.
As before, the momentum pushed both of them back against the rear of the capsule. Derec was too sore to brace himself with his arms, so his head and shoulder were jammed against the back surface. They were rushing through darkness, blasted by the air that swept over them from unseen vents.
Before, the flight from their pursuers had kept his adrenaline flowing, and he had experienced some remission of his stiffness. Now even the excitement of riding the vacuum tube was not enough to keep the symptoms from recurring. His legs continued to throb painfully, and the shooting pains in his back seemed to settle in with the increasing stiffness he felt.
His one relief was that she was right. They had not left a trail.
The tube curved upward. He closed his eyes in antic.i.p.ation of light, and brilliant sunlight flooded the capsule. Opening his eyes slowly so they could adjust, he took in the new scene around them.
This section of the transparent vacuum tube rose high above the ground and used the existing supports of various buildings to wind over the city. At this alt.i.tude-and it was still rising-it would not interfere with earthbound priorities. Their capsule was shooting along the tube at high speed over what should have been a spectacular view. He was in too much pain to enjoy it.
Suddenly a thought struck him.
"Ariel," he said, with effort. "That entire staff at the Key Center has been rea.s.signed. But it was the Key Center that provided the vacuum to run this vacuum tube system. That means the Key Center itself is still working. What"s going on around here, anyway?"
She didn"t answer.
"Ariel?" He called louder over the rushing air, but he knew what her silence meant. With a sinking feeling, he turned his head to look at her, feeling more snappings in his neck.
She lay on her back, holding herself in position by pushing against the rear of the capsule with both hands. Her face, turned to the side, showed exhilaration and excitement as she gazed at the panorama of the city. She did not seem to see him at all.
Derec guessed that she was reliving their first wild ride in the vacuum tube, long ago. It was a happier period in some ways, though they had felt burdens at the time. At least he had been healthy, and she had been functionally so before her disease had really struck.
He turned his face away from her. If she was reexperiencing those memories, she was probably more comfortable at the moment. He could let her have that. Then, once they were safely out of this capsule, they could get their bearings.
The tube did not always go straight. Its various straightaways were broken with curves, loops, and changes in alt.i.tude. These most often simply accommodated architecture that must have been already in place. Sometimes they brought the capsule to an intersection of tubes, where curves allowed it to change direction with minimal loss of speed. Occasionally the shifts in direction led by depot sidings that their capsule shot past. Every so often the tunnel dipped underground, and once it ran along the ceiling of the platform booth tunnel system for an extended period.
Finally the capsule leveled off near the ground and decelerated sharply into a siding. It stopped abruptly, sliding them both to the front of the tube with the small package. Derec lay panting on his back, looking up through the transparent capsule and tube at the impa.s.sive face of a Hunter robot.
The slidewalk was the slowest of Robot City"s powered transportation systems. Mandelbrot and Wolruf followed the single Hunter on it with increasing boldness. The various Hunters had obviously taken different a.s.signments and they had no way of knowing what role this Hunter actually had.
"Not too close," hissed Wolruf softly over Mandelbrot"s shoulder. " "U will get itss attention, I tell "u."
"I doubt it," said Mandelbrot. "I now think it, as a Hunter, maintains an awareness of everything around it. It must have scanned us and rejected us as its quarry."
"That iss sstupid," said Wolruf.
"Eh?" Mandelbrot said stiffly.
"Not "u. "Im," she said patiently. "Why would theirr order include Derec and Ariel but not us?"
"It does seem to be poor programming," said Mandelbrot. "However, I do not judge it as stupidity."
"Then what?"
Up ahead, the Hunter still advanced along the moving slidewalk. It seemed to know where it was going.
"Derec often spoke of the single-rnindedness of Avery robots," Mandelbrot explained. "Their task orientation is narrow. If the central computer or the Supervisors, or even Avery himself, learned of the presence of Derec and Ariel, perhaps the order to the Hunters specifically named them and did not extend to anyone else."
Wolruf shook her head at the Hunter ahead of them. "Iss stupid. Good for us, but still stupid."
Ahead of them, the Hunter moved on. Mandelbrot strode tirelessly after it.
Derec and Ariel were in no shape to protest as two Hunter robots lifted them out of the capsule door. The function robot on the dock waited until the humans were out before grabbing the small package that had been scheduled for the trip. Derec hurt allover and was simply too weak to struggle.
One Hunter held him by the arm, and he actually leaned against the robot for support. Ariel was just now blinking at the Hunter holding her. He recognized that as one of the signs that she was coming back out of her latest memory fugue.
"Ariel," he said quietly.
She turned at the sound of his voice, then started at the sight of the Hunters. "Derec-"
"They"ve got us," he muttered wearily. He shook his head as the Hunters turned and started for the nearest slidewalk, pulling them along in their inflexible grips.
Derec still tried to think of a way out of this. They were positronic robots and would respond to protests based on the Laws. From past experience, however, he also knew that they had been programmed to detain and arrest humans without harming them. He could argue, but he didn"t know how to win.
Besides, he was just too tired. Derec stumbled several times, forcing himself to keep up with the Hunter. Finally the Hunter lifted him bodily and carried him, not out of concern but for efficiency of travel. The other Hunter lifted Ariel at the same time.
The Hunters turned to ride the slidewalks and Derec found himself facing Ariel.
"How did they get us?" She mouthed the words silently, with a quick glance at her captor"s head.
"I don"t think they care if we talk," he said aloud. "I"m guessing now that some other Hunters started by questioning the tunnel-system computer. That gave them the coordinates of the tunnel stop where we got off the platform booth, as I was afraid might happen. From there they must have used heat sensors to track us along the street to the vacuum tube depot."
"But the capsule in the vacuum tube goes so fast. How did they get in front of us?"
"They must have found out which depot that package was going to and called ahead to have these guys waiting for us."
"After that long ride," said Ariel. "You make catching us sound so simple."
"Apparently it was," he said ruefully.
"They"ve got us," she said, in a voice that cracked. "Derec, look out! They"re right behind us in the conduit-"
Derec stared at her in a kind of resigned worry as she entered another displaced memory episode. This one must be from the last time Hunters had tracked them down and captured them, when they had tried to run away through the maze of underground conduits in the city. The vacuum tube hadn"t worked any better.
He ached allover. Having the Hunter carry him was almost a relief after the effort to escape. Ariel was squirming and protesting in the grasp of the other Hunter, but she had no idea of where she was or what was happening now. He closed his eyes and tried to relax.
The Hunters only rode the slidewalks a short distance. They were soon intercepted by a large function robot in the shape of a transport truck. The Hunters mounted the open back of the truck, still carrying Derec and Ariel.
The switch to the truck woke Derec up, and he watched the city pa.s.s by as they rode. Ariel was now silent, her eyes closed. The city streets seemed depopulated to him, at least compared to what he remembered from their previous visit to Robot City. Maybe, he thought, the city had expanded faster than the robot population, causing the robots to spread themselves thinner over the whole planet.
He glanced at Ariel periodically with growing concern. Her episodes seemed to occur more frequently under stress. That might mean she was getting worse, not better.
The truck stopped several times to pick up other Hunters from the slidewalks. Now that the search was over, they would probably be taken to a storage area or something. They were all unusually tall for humanoid robots, with expansive torsos. Narrow benches molded from the truck bed itself provided seats for all of them along the side walls. They sat with their knees drawn up and their waists level with the top of the walls, watching Derec and Ariel without a word spoken.
The truck slowed down as it approached one more lone Hunter on a slidewalk. Two familiar shapes caught Derec"s eye in the distance, and he stiffened.
"Ariel," he said quietly.
She didn"t answer.
He glanced over his shoulder at Mandelbrot, who was standing on the stationary shoulder of the slidewalk just a few meters away. Wolruf had been with him a moment ago, but was now out of sight. The Hunter was climbing into the back of the truck, making a total of six. Derec reached over and shook Ariel"s limp arm.
"Ariel."
She opened her eyes and looked at him, still partly disoriented. "What? Derec, where are we?"
It was too late to get off the truck, even if the Hunters could be distracted somehow. The last Hunter was on board and the truck started up. Then the engine began a high, irregular whine and the truck coasted back to a stop.
The Hunters remained motionless for a short time. Then Mandelbrot stepped forward. Derec was certain that they were all communicating through their comlinks.
"What"s going on?" Ariel whispered.
"I"m not sure."
Mandelbrot suddenly climbed onto the front of the truck and sat down. Derec had trouble seeing what he was doing, but a minute later the truck began to move forward, Hunters and all. Apparently Wolruf had sabotaged the function-robot brain and Mandelbrot had successfully volunteered to operate a manual override. Derec hoped Wolruf was safe, wherever she was-most likely under the truck and hanging on precariously.
By now, Ariel had also recognized Mandelbrot. She and Derec exchanged puzzled glances, still in the firm grip of the silent Hunters who had taken custody of them. They watched the Hunters carefully as the truck picked up speed and rolled along, but the robots seemed perfectly content with the situation.
Soon Mandelbrot had the truck up to a considerable velocity, much faster than the truck had driven itself. The Hunters gripped the sides of the truck to stabilize themselves. Derec did not feel any loosening of the hold on him, however.
Mandelbrot was going to try something to free them. Derec tensed himself in antic.i.p.ation.
He was not too surprised when the truck suddenly took a sharp left that sent everyone in the back sprawling. With a hard, painful yank, he wrenched himself free of the Hunter holding him, knelt on the bed of the truck, and got leverage under the robot. He gave a heave and flipped the Hunter clean out of the truck.
Next to him, Ariel had almost pulled free of the Hunter holding her before it regained its balance. All of them leaped to their feet to restore order, but Derec shouldered another Hunter into the one grappling with Ariel. The truck took another sharp turn and all the Hunters stumbled again. Derec watched for anyone to become overbalanced toward the edge of the truck bed and managed to shove another one out of the truck.
Their ma.s.sive size and great strength had become a liability on the unstable truck bed.
The vehicle came to a sudden, screeching, careening halt that threw everyone in the back forward. Mandelbrot, who had been braced for the stop, leaped into the back of the truck and hoisted out another Hunter who was still in the act of standing up again. Mandelbrot rolled one more out on top of that one and then pulled Derec free of the one grappling with him.
Mandelbrot"s great advantage became clear to Derec. The first priority programmed into the Hunters was to find and detain the two humans. The First Law"s demand that they not harm the humans overrode the Third Law"s requirement that they protect themselves.
While the remaining two Hunters grappled with Derec and Ariel, Mandelbrot was able to get the right leverage under each Hunter and lift them out of the truck.
"Hang on," Mandelbrot called out in a remarkably calm voice. He jumped back to the manual console in the front and drove off.
Derec fell back on the bed of the truck, gritting his teeth in pain but relieved that they had escaped. Ariel scooted over to him and sat down, her hair blowing in the breeze.
She smiled faintly. "That was close. How did they-"
"Look out!" He shouted.
Behind her, over her head, one of the Hunters was climbing up the side of the moving truck, where it had gotten hold before the truck had started again. Derec tried to stand, but the pain in his legs was too great. His feet slipped and he fell back again.
The Hunter was just climbing over the side when it suddenly vanished from sight and hit the street with a crash.
Then Wolruf"s head appeared over the side with her caninoid grin. "Hunterr poorly balanced," she said, climbing over the side.
Ariel jumped up to help her over.
Mandelbrot turned another corner on the city street, then another. After speeding quickly down another block and taking one more turn, he came to a stop, a smooth one this time.
"What is it?" Derec called, but he was too uncomfortable to get up. "Ariel, find out what"s going on."
"Mandelbrot?" Ariel said, standing.
Derec could hear both their voices.
"This vehicle has a comlink that must be fully disconnected," said Mandelbrot. "Wolruf successfully disconnected the function-robot brain from the truck controls, but it still works, and the central computer may be able to locate our position through it. However, as soon as I finish disabling it.... There."
Derec heard a heavy object hit the pavement alongside the truck.
"The truck is now comlink invisible," said Mandelbrot. "We cannot be tracked through it. We are free to move about." He sat down at the console again and drove off.
Derec let out a long sigh.