It was difficult to hear anything above the racket Derec and Mandelbrot made moving through the woods. Derec quickly realized that there was no hope he’d be able to survive by hunting for food. He’d starve first.

They’d seen very little wildlife except during their rest periods. Otherwise, whatever animals lived here simply fled from the clamor of their passage. Shapes skittered through the trees ahead of them, birds took to the air with shrill cries. But a new sound intruded, making Derec cock his head quizzically.

“Did you hear that, Mandelbrot?”

Derec had stopped, leaning on the walking stick he’d cut from a dead branch and breathing heavily. They were struggling up a slope tangled with dense, close underbrush and tenacious, sticky-leaved vines; the place seemed to have been designed to give them trouble. The sun was already behind the hill and dropping rapidly, and Derec’s legs itched wherever the plants had scraped skin through his clothing. Mandelbrot, ahead of him and sounding in dire need of an overhaul, was moving very slowly with his malfunctioning leg. The robot stopped and turned his head around, the neck grating metallically.

“I have heard several things, Master Derec. Which sound were you referring to?”

“The howling. There-you hear that?”

Very faintly, a mournful wail greeted the dusk. Another voice joined the first, then several others. The mournful chorus continued for several seconds, then went back to the solo voice once more. The forest seemed suddenly very dim and dangerous. Derec shivered involuntarily.

“That sends cold chills down my back,” he said.

“There are thermal blankets in the pack,” Mandelbrot told Derec. “Let me get one for you-”

Derec smiled. “It’s not that kind of chill. It sounds like recordings I’ve heard of wolves-made before they became extinct.”

The barking howls began again, echoing and reverberating among the slopes. Mandelbrot’s neck joint screeched again as the robot looked up slope. “Their voices are complex,” he said. “In some ways it reminds me of Wolruf’s language. “

Mention of the caninoid alien’s name made Derec nod; he missed Wolruf, missed her quick wit and odd temper. “I wish it were, believe me. At least then we might get out of this mess. We have to find a place to camp for the night, Mandelbrot. Any level and halfway open space will do. I don’t want to get caught out here in the open during the dark.”

“My data banks say that even in the days before Earth was settled, most wild animals were afraid of humans. They very rarely attacked anyone without provocation.”

“Well, I’m not going to count on them having been fed the same data. Let’s keep going, Mandelbrot. Maybe at the top of this hill…though from the size of it I’m beginning to think we should promote it to mountain.”

It took them another hour to struggle to the summit. There, the trees thinned out and finally disappeared on a wind-swept, rocky ledge that, looming above the surrounding hills, gave them an excellent vantage point.

Every last muscle in Derec’s body ached from the exertion of the climb. His broken arm throbbed and burned; he was breathing in quick gasps, afraid to breathe any deeper because of his ribs. Derec swung his pack down with a grimace and found the medical supplies. An EndPain injection allowed him to keep moving. Mandelbrot, every joint rasping, helped Derec inflate the tent and arrange their pitifully few supplies. Derec started a small fire in a circle of rocks, and they sat on the hilltop watching the stars appear in the dark blue of the zenith, sprinkled across the sky in their millions.

“They certainly are persistent, those wolves or whatever they are.” The howls had continued to serenade them as they’d made camp. They seemed to be coming from the west, in the same general direction they were heading though several hills over. Derec sat on the edge of the ledge and tossed pebbles into the trees below, listening to them crash through the branches. He looked at the shadowy landscape ahead of them and grimaced. “Look at that. You’d figure the hills would all have to run north and south-we’re going to walk five kilometers up and down for every one due west.”

Derec glanced over at the robot standing alongside him. It didn’t seem to have heard. “Mandelbrot?”

“I am sorry, Master Derec. I was listening to them.”

“Just make sure they don’t get closer.” Derec threw another stone, then squinted toward the west. “How well are you seeing, Mandelbrot?”

“My night vision is very poor due to the crash damage. It is no better than yours.”

“Uh-huh. Take a look anyway and tell me if that isn’t a glow in the northwest, maybe four or five of those hills over. I didn’t notice it before, but with the darkness-”

Mandelbrot peered in the direction Derec was pointing. “I see a patch of light reflecting from underneath clouds…”

Then, for a moment, they were both silent, listening to a voice that whispered in both their heads.

All units: central computer under attack. All units… .

The voice was very faint. It faded even as Derec tried to get the voice to respond.

“My fa-” Derec began, then stopped himself. He hated the man too much to call him that, and on Aurora it meant very little anyway. “Mandelbrot, it must be Avery.”

“It is possible. “

“It’s more than possible. It explains everything: the distress call, the central computer not responding to the chemfets, our crash-landing-everything. He could have used a Key, jumped to the Compass Tower here, and started disrupting the city.”

“Why?” Mandelbrot asked. “The first Robot City was his creation. “

“He was also very disturbed that I could control it. Maybe he’s decided to destroy all the others.”

“It is possible, I suppose,” Mandelbrot admitted. “But we will not know until we arrive.”

“We have to push harder, Mandelbrot. The city’s in trouble.”

“Why should that concern you so much, Master Derec?”

The question sounded like one Ariel might have asked, and the reminder hurt more than his physical pain. Derec scowled. “It just does. Maybe it’s the chemfets-some chemical bonding with the city that’s due to them. I don’t know, Mandelbrot. All I can tell you is that I hurt when the city hurts, and it makes me want to do something about it. Can you understand that?”

“I can, Master Derec. What you describe sounds very similar to the compulsion of the Three Laws within every robot. And if we must push ourselves tomorrow, I would suggest that you rest,” the robot said gently. “You are exhausted, and I cannot carry you.”

Derec wanted to argue, but Mandelbrot was right. He could feel the weariness; and the effort it took to get to his feet convinced him. “Then I’m going to try to sleep. What about you?”

“I do not know how much longer I will be able to walk. The less I move, the better. I will stand here and watch. Have a good sleep.”

His dreams were haunted by his father, who could take on the shape of a wolf. Ariel was there, but wolf-Avery chased her away, and though Derec tried to run after her, his feet were leaden and horribly slow.

Derec awoke with a start. For a moment, he was disoriented and nearly panicked until the nagging pain in his arm and ribs reminded him. He opened the tent and poked his head out through the flaps.

It was still dark. Two moons were in the sky; one high, the larger one low to the west. Backlight against the moonlight, he could see Mandelbrot, standing motionless at the edge of the overlook and staring out into the night. He could hear the wolf-creatures baying at the moon.

“Mandelbrot?”

“Everything is fine, Master Derec. I was listening to them. Their voices; it is almost like a language.”

‘Their voices make me want to avoid them at all costs. They’re probably discussing how tasty my bones and your metal would be. Good night, Mandelbrot.”

“Good night, Master Derec.”

He lay there for a long time in the darkness, not wanting to go to sleep. He didn’t know if it was because Avery would be waiting for him in his dreams, or because he was afraid Ariel would not.