“Ready,” Derec said.

“Warning: reduced gravity beyond this point,” the hatch advised him.

“I hear you,” he said as the outer door began to open. Nitrogen? Low-G? he wondered as he stepped out. Where am I? What’s going on?

There were no immediate answers. It was cold-cold enough to bring a flush of color to his cheeks. The chill seemed to radiate equally from the ceiling and floor, though they were both made of an insulating synthetic mesh.

Standing there just outside the pressure hatch, Derec could hear a cacophony of machine noises-hissing, rumbling, grinding, squealing. But the drop in pressure, which distended his eardrums, made it seem as though he were trying to hear through a pillow. Aside from the fact that there was activity somewhere, he got nothing useful out of what he heard. He could not tell what kinds of machines he was hearing, or what they were doing.

Determined to follow the sounds to their source, he started down the corridor-or tried to. He ended up flat on his face on the cold decking, uninjured but chastened. Collecting himself, he tried again, this time pulling himself along the corridor by the center handrail.

Thirty meters ahead, the corridor opened into an enormous low-ceilinged chamber. Derec gaped as he took in its dimensions. It suggested armories, playing arenas, open-plan factories. He forced a yawn and swallowed hard, and the pressure in his left ear equalized. Yes, those were definitely machine noises. But what kind of machines, doing what kind of work?

Between the cold and low gravity, Derec concluded that he was still on the asteroid where his lifepod had crashed. From the structure of the chamber, he concluded that he was most probably underground.

More important, he was not alone. There were robots moving among the stacks and aisles-dozens of them, of a half-dozen varieties. But in another sense, he was alone, for there were no other people. There were not even any handrails in the aisles to make the chamber human-accessible. The chamber belonged to the robots by default. What task they were so busily attending to, he could not divine.

The nearest of the robots, a squat boxlike unit with a single telescoping arm, was only a few dozen meters from Derec. As Derec watched, it plucked a fist-sized component from a rack, stowed it in a cargo basket, and retracted its manipulator arm. Its mission apparently accomplished, the robot started away, coasting on a cushion of air from under its venturi skirt.

“Stop!” Derec called out.

But the robot continued on, seemingly deaf to Derec’s command. On impulse, Derec released the handrail and went in pursuit. But in the asteroid’s minimal gravity field, it was like trying to run with both legs asleep. He was perpetually off-balance, his slippered feet failing to give him the traction he expected. When he came to his first ninety-degree turn, he went sprawling, scattering a rack of small chromium cylinders.

Not even the racket from his spill slowed the robot’s retreat. It continued on toward what appeared to be a lift shaft-a circular black pit in the floor and a matching one in the ceiling, linked by four chrome guide rods.

“How am I supposed to catch you?” he complained, climbing to his feet. “Ican’t fly.”

There had to be a better way, and looking more closely at two robots heading down the aisle toward him, Derec saw what it was. Unlike the picker, the man-sized robots were built on standard three-point ball-drive chassis-like three marbles under a bottle cap. Ball-drive chassis were standard in clean environments because they offered complete freedom of movement. The drawback: here, with the reduced friction due to the low gravity, the drive balls should do more spinning than pushing.

But each large robot had a second ball-drive chassis mounted at the top of a telescoping rod. Pushing against the ceiling, the second chassis provided the necessary pressure for the dual drives to grab. Like the bumper cars at a revival carnival, each robot needed to be in constant contact with both surfaces to operate.

Derec realized that he could use that trick, too. The ceiling was low enough that he could push against it with his fingertips while standing flat-footed. “Hand-walking,” as he dubbed the technique, he could have caught the picker.

Now he waited to see what the two approaching robots would do about him. They stopped short of where he stood and began to restore order where he had fallen down, deftly using their three-fingered grapples to replace the cylinders on the shelving. He waited, wondering if they would notice him. They did not.

“I’m in danger,” he called to them. “I need your help.”

The two robots continued their housekeeping, apparently oblivious to his presence. He drew closer and examined the nearer of the two as it worked. It had normal audio sensors, but no evidence of a vocalizer. In short, it was mute. It could not answer.

But there had to be some higher-level robots in the complex, ones capable of recognizing him for what he was and responding to his needs. The pickers and custodians he’d crossed paths with could hardly be working without supervision.

Likewise, the E-cell he awoke in couldn’t be the only structure for humans within the complex. Somewhere there was a management team, programmers, supervisors. There was no such thing as a completely autonomous robot community.

Thinking that there had to be a way to call the control room from the E-cell, Derec started back. As he did, he saw a sight that brought him up short. A tall humanoid robot was standing at the end of the corridor to the E-cell, studying him.

They stared at each other for a long moment. The robot’s skin was a gleaming pale blue, a vivid declaration of its machine nature. Its optical sensors were silver slits in its helmet-like head, lacking the customary red tracking marker which telegraphed when the robot was looking in your direction. Even so, there was no doubt in Derec’s mind that he was the object of the robot’s rapt and unnaturally focused attention.

The robot was the first to move, turning away and disappearing into the corridor, hand-walking with easy coordination. Derec followed as quickly as he was able, but by the time he reached the corridor, the robot was already inside the airlock. It took no more than fifteen seconds for Derec to reach the outer hatch and pass through into the E-cell. Even so, when he stepped out into the inner corridor, the robot was already emerging from the wardroom, its business apparently finished.

“I’m in danger,” Derec said. “I need your help.”

“False assessment: you are not now in danger,” the humanoid robot said. “Should you be in danger, help will be provided.”

The robot took one step toward the pressure hatch, and Derec moved to place himself in its path.

“I’m not letting you leave here until you tell me where I am and what I’m doing here,” Derec said sharply.

The robot’s answer was nonverbal but perfectly clear. Stepping closer, it grasped his shoulders firmly but gently and moved him out of the way. Then it walked with smooth strides past him to the hatch.

“Open,” it said.

Feeling helpless, Derec let the robot go, then turned to see if he could discover what it had been doing in the wardroom. Only two things had changed since Derec had left. The galley was still counting down to full Demand status, but the selector was now showing a short list of selections that were already available. Derec himself had set that change in motion.

It was the other change that the robot was responsible for. The screen of the com center was no longer blank. In bright red letters, it reported: MESSAGE TRANSMITTED.

It was then that Derec knew for certain that he was alone on the asteroid. The fact that there was an environmental cell deep under the surface implied that there had once been at least a temporary human presence here. But this little world was in the hands of the robots now, and he was a trespasser. What message they had sent about him, and to whom they had sent that message, there was no telling.