“The time,” said Derec. His anger flared, giving him energy. “We just don’t have much time. Sure, I think we-or they, anyhow-can find Avery sooner or later. But it may be too late for me.”

“After everything that’s happened to us? You’re going to give up now? Come on!”

“Well, what can I do? Just lie here?”

“Maybe we can still think of something. We got away from Aranimas, didn’t we? We got out of Rockliffe Station, and we solved the shapechanging and the murder mystery-or I should say, you did…” Her voice trailed off.

He waited a moment, expecting her to continue. When she didn’t, he looked up at her.

She was staring at him with horror on her face. Startled, he raised up enough to look himself over, but saw nothing unusual. He passed his hand in front of her face but she did not react.

“Ariel,” he said firmly.

“It’s Derec,” she whispered. “He looks just like Derec. It’s impossible.” Suddenly she turned and leaped off the bed, only to run into the desk almost immediately. Her legs buckled and she thumped hard on the floor, blinking rapidly.

Derec forced himself up on one elbow and reached down to grip her arm. “Ariel. Can you hear me?”

She was looking around the room very slowly. At first she didn’t seem to hear him, but then she nodded, almost imperceptibly. “You’re up,” she said, surprised.

“Not very far.”

She reached back with her hand and slapped him across the face hard, leaving his cheek stinging from the blow.

Derec sat up straight, swinging his legs over the side of the bed. “Are you crazy? What-”

“Look at yourself!”

“Myself? What are you talking about?”

“You’re sitting up. Derec, you have to stay alert. I don’t know if it’s the adrenaline or the fear or the, the…I don ‘t know what. But when I went into a fugue state again, the emergency started bringing you back to normal.”

“And then you hit me…and I sat up.” Derec nodded slowly. “I’m hardly back to normal, but I see what you mean.”

“Don’t give in to it, Derec, You have to fight it.”

“All right. I get it. It’s like cold when you’re in danger of freezing. You have to move around and keep the blood circulating. Something like that.” He stood up, and winced at the stiffness in his joints. “I still hurt allover.”

Ariel rolled the desk chair into position for him. “Come on. Back to the terminal. The work will keep your mind busy, and maybe we’ll think of something useful.”

Mandelbrot realized the time had come for him to rendezvous with Wolruf. Since he might still benefit later from acting within the city matrix, he did not want simply to abandon his duty. Tamserole had not returned, so he took the greater risk again of reporting to the central computer.

“This is the Priority 4 Regional Contingency Power Station. I am reporting a leave of duty because my supervisor is not present to receive it.”

“WHERE IS YOUR SUPERVISOR?”

“I do not know. He is fulfilling his duty elsewhere.”

“WHY ARE YOU LEAVING YOUR DUTY?”

“I have an emergency.”

“EXPLAIN IT.”

“I do not have time.” Mandelbrot broke the connection, hoping that he would be able to return to duty here later if it would be useful. He did not have an explanation yet. Attempting to create one could wait until it was necessary. Considering the immense size of the central computer and its total data, the oddities of his behavior might still escape the notice of Dr. Avery.

Mandelbrot had spent his relatively brief time at the station actually performing his duty. He had made some progress in creating an autonomous system that would free Tamserole to activate migration programming, but he had not quite finished it. If he had, he might have been able to leave without suspicion. He was not certain.

One problem Mandelbrot faced was that he was intellectually distinctive from the robots of Robot City and at any time might reveal his differences by the questions he asked or the actions he took.

Mandelbrot rode down the ramp of the tunnel stop and saw the little alien sitting calmly to one side of the loading area. She was in a slight shadow, out of the way of robots getting on and off the platform booths. When she saw him, she stood up impatiently.

Mandelbrot did not speak right away. Instead, he lifted her onto his back and stepped into one of the booths, where they would not be overheard by accident. The booth would not start until it had a destination, so he entered the one for the Compass Tower. They could change their minds later if necessary.

“Have you learned something?” he asked once the booth was on its way.

“Yess,” Wolruf hissed eagerly. “Robots moving everywherr. Change city so that fewer robots arr needed at each place. Then they leave theirr dutiess.”

“The migration programming. Do you have any clues about what that means?”

“No.”

“I don’t want to take the risk of asking the central computer myself or asking through the station terminal, for fear of attracting too much attention. We’ll have to return to the office.”

“Good,” said Wolruf, with her caninoid grin. “Getting hungry now, anyway.”

Derec was forcing himself to sit up at the terminal despite the painful stiffness in his back. He had been asking the central computer all kinds of questions, anything either he or Ariel could think of, shooting wildly in the dark. So far, they had not discovered anything that led them anywhere.

The blank screen shone patiently in his face. “Any more ideas?” he asked her.

“What about those robots at the Key Center? If my memory serves-” She smiled at the irony. “If it serves, they seemed to be chosen for their high quality. What are they doing now?”

“Good idea. Let’s see.” Derec asked, “What activities are underway at the Key Center?”

“NONE.”

Derec straightened in surprise. “Where is Keymo and the team of robots assigned to him?”

“KEYMO IS AT THESE COORDINATES.” The central computer gave some numbers. “NO TEAM IS CURRENTLY ASSIGNED TO HIM.”

“What is he doing?”

“HE IS FOLLOWING HIS MIGRATION PROGRAMMING.”

“What are the other robots doing?”

“THEY ARE FOLLOWING THEIR MIGRATION PROGRAMMING.”

“Where are they?”

The computer responded with a long list of coordinates. They represented a very wide range of locations. Most of them were on parts of the planet far from here at the heart of Robot City. These locations had not even existed as part of the city when Ariel and he had first arrived. Some coordinates, however, were listed more than once. Keymo’s location was included.

“What pattern of significance do these coordinates represent?” Derec asked.

“THEY ARE PRECISELY 987.31 KILOMETERS APART. THE PATTERN COVERS ALL THE LAND SURFACE OF THE PLANET.”

“Why?”

“THIS DISTANCE RESULTS IN EXACTLY THE NUMBER OF ASSEMBLY POINTS DESIRED.”

Derec felt a surge of excitement. “Desired by whom?”

“DESIRED BY THE PROGRAM.”

“What is the purpose of the program?”

“ACCESS DENIED.”

Derec slapped his hand on the desk. He was too weak to hit it very hard. “So this terminal is blocked now, after all. We just didn’t ask it the right questions before to turn up the blocks.”

Behind him, Ariel said nothing.

“I wonder. If Avery put some blocks on this terminal as a precaution before we got here…why didn’t he put the standard blocks in? Why did he ignore most of the blocks the other terminals have but leave some of them?”

On the screen, the words “ACCESS DENIED” taunted him silently. On the walls all around them, Robot City bustled in the shining day. The room was silent.

“All right,” Derec said to himself. “Maybe the block really isn’t on this terminal. He’s set himself up somewhere else, of course, and he’s simply blocked whatever he’s done at that terminal. That must be it. He hasn’t thought to block this one. Makes sense, doesn’t it?”