“The shapechanging has to be stopped,” said Ariel. “It’s causing the massive rainstorms every night.”

“What?” Derec turned to stare at her.

She clutched at his chest, looking over his shoulder at visions only she could see. “The floods. They’re caused by the shapechanging mode in the city’s central core. We must stop it!”

Mandelbrot had already left the terminal and was gently reaching out to pull Ariel away from Derec.

“It’s just a temporary relapse,” said Derec quickly. “It doesn’t mean she’s getting worse. Understand?”

“I understand,” said Mandelbrot. He was easing Ariel into a sitting position on the bed. “You know, however, that discussing the shapechanging mode a short time ago did not trigger a relapse. Her condition is inconsistent at best.”

“Apparently her memories aren‘t anchored in a chronological perspective.” Derec paused, still watching Ariel. His impulse to hold her, to protect her, was held in check by his fear of somehow making the relapse worse.

Her eyes were closed and she was taking short, shallow breaths. She was sitting up on her own, though. Gradually, her breathing slowed down and approached normal.

Satisfied that she was out of immediate danger, Derec continued with his thought. “Something triggers a memory, and she relives it as a current experience. Or at least, it seems that way so far.”

“A bad experrience,” said Wolruf.

Ariel seemed to be gaining her composure. Derec looked out at the city again. He was sure that the unfamiliar skyline had not resulted from the old shapechanging mode, but was simply the result of constant refinement on the part of the robots.

Suddenly he moved to the terminal and entered another question. As before, he made a number of errors, far more than usual. He slowed down and typed them correctly. “Is the city functioning under any defensive overrides of the type represented by the shapechanging mode it once entered in response to parasites in human blood?”

“NO.”

“Is it operating under any overrides to basic programming?”

“NO.”

He stared at the screen, somewhat disappointed. “Is something wrong?” Mandelbrot asked.

“Not exactly. I was just thinking that if the city was under an emergency of some sort, I might have been able to use it to our advantage somehow.”

“If Dr. Avery is on the planet, he probably would have dealt with an emergency already,” said the robot.

“Or maybe he left, but no crisis has arisen.” Derec shook his head in resignation. “He could be literally anywhere, with a Key to Perihelion. Or with all the Keys the robots could duplicate, for that matter.”

“It’s not shapechanging any more, is it?” Ariel was gazing out at the city.

Derec and Mandelbrot both looked at her in some surprise.

“No,” Derec said, relieved. “We ended it a long time ago. That danger is passed.”

She nodded, still gazing out at the city.

He watched her for a moment and decided that leaving her alone might do her more good than grilling her with questions. She was self-conscious enough already, though her quick recovery from this episode was encouraging. He just hoped that he was right about her not needing treatment by the robots. Then he saw Mandelbrot studying her, also.

“Mandelbrot,” Derec said firmly. “Her relapse is over.”

“It may recur, I surmise.”

“Another one may occur, but I don’t think the same one will.” Derec hesitated, thinking about the two episodes he had seen since they had returned here.

“We have compiled very little evidence for that conclusion,” said Mandelbrot.

Derec shook his head. “I think that every time something of that sort happens, her memories are integrated just a little more afterward. It’s part of the growth and replacement process that I didn’t recognize at first.”

“I understand the principle,” said Mandelbrot. “How certain of this theory are you?”

“Uh-” Derec saw Ariel watching him.

Her face reflected more anxiety than he had ever seen her express, even at the worst of her disease.

He looked back at the robot and cleared his throat. “I’m sure of it. Remember, the growth of her memories and identity was intended all along. These episodes are just…growing pains.”

Ariel closed her eyes in relief.

Derec sighed. He felt as though he was juggling too many lines of thought at once-Ariel’s recovery, Mandelbrot’s possible First Law imperative regarding her, and his own failing condition. What he really should be doing was finding Dr. Avery.

He took a deep breath and tried to focus his thoughts once more. “All right. We can figure that Avery has hidden all direct evidence of his whereabouts from the central computer. We’ll have to cast around for indirect evidence that he didn’t intend to leave. Anyone have any suggestions?”

Ariel looked at him for a moment and then returned her gaze to the viewscreens with a slight shake of her head.

Mandelbrot stood quietly, apparently reviewing and rejecting possibilities.

“We can’t find him by staying here in this room, can we?” Derec spoke softly, admitting what none of them wanted to say.

“The principle of identifying useful questions and seeking their answers through the central computer is sound,” said Mandelbrot. “Theoretically, the search could be narrowed a great deal in this manner if we ask the right questions.”

“And if we can’t?” Derec demanded irritably. “What then? Maybe we don’t have enough information to figure out the right questions, no matter how long we sit here.”

“Leaving this office to explore the planet greatly increases the danger to you,” said Mandelbrot.

“Now don’t you start more First Law objections. Sitting here doing nothing will eventually harm us the most.”

“I am not arguing against leaving itself,” said Mandelbrot calmly. “I do recommend a specific plan of action.”

Derec shrugged in agreement. “Like what?”

“That has yet to be identified.”

“We’re going around in circles!” Derec threw up his arms in frustration. He banged one hand against the desk when he lowered it and grabbed it in surprise.

Wolruf was watching him again.

“I suggest that Wolruf and I go out first,” said Mandelbrot.

“How so?” Derec rubbed his hand surreptitiously, pointedly ignoring Wolruf.

“Consider this. As a robot, I do not attract undue attention here. On our first sojourn through Robot City, Wolruf was of no particular interest to the robots of this community. We have the best chance of gathering information and returning here safely to report it.”

Derec thought a moment. ‘The terminal here confirmed your report that no special alerts are out. So the robots aren’t on the lookout for humans, particularly.”

“The presence of humans, however, will at the very least trigger the applicability of the Laws of Robotics. If their behavior is changed because of the Laws, even in small ways, the shifts may be noted by the central computer and attract the notice of Dr. Avery.”

“You mean if I instruct a robot to tell me something, he might be late fulfilling his duties or something.” Derec nodded slowly. “With someone as paranoid as Dr. Avery, I guess maybe those small variations might cause a review…if he noticed them.”

“I am calculating probabilities only, of course,” said Mandelbrot. “I am balancing potential benefit against possible danger.”

Derec realized, suddenly, that he welcomed the chance to rest. He didn’t think of himself as a coward, or feel afraid. In fact, the Robot City he remembered had not been nearly as dangerous as Aranimas, the pirate. Still, he just didn’t feel right. Maybe he should lie down.

“All right, Mandelbrot,” he said. “You two go. We’ll stay here.”