Steve glared at Hunter but said nothing.

Marcia glanced at Steve haughtily. “I suppose this makes sense. We have to fit into their society as smoothly as we can. I can tolerate some masquerading.”

“Steve, do you agree this is logical?” Hunter asked.

“Yeah, I guess.”

“We should present ourselves as visitors from a southern province,” Marcia added. “This will explain any accent in our speech and unfamiliarity with details of Khanbaliq that never appeared in the history I have studied. We don’t want to present ourselves as native to the city and then reveal our ignorance at the wrong moment.”

“Which province do you suggest?” Hunter asked. “We should agree on one now.”

“I recommend Guangdong, which is the southernmost province. We won’t be likely to run into others from there who will expose us.”

Steve nodded.

“And you must have some career, in case people ask what you do.”

“Okay.” Steve shrugged. “Like what?”

“A peasant or ordinary working man isn’t likely to travel across the country in that time. I think you should be a scholar seeking a government appointment.”

“Me? A scholar?” He grinned, glancing at Jane self-consciously.

“The top bureaucratic appointments in this time went to foreigners because Kublai Khan did not trust the Chinese. Many of the Turks and Persians I mentioned were in high government posts. Also, many of the established scholars refused to serve the Mongol government, even at the provincial and local levels. However, some young Chinese scholars managed to get into the lower ranks of the imperial offices. You’re the right age.”

“This sounds reasonable to me,” said Hunter.

Steve sighed. “Okay.”

“Marcia, I have much more to explain to you,” said Hunter. “Time travel is the exciting part of the mission, but I must inform you of some background information. Have you been following the news today? Particularly, the explosion that destroyed Beijing? Millions of people died and China is in chaos, and has no government.”

“The nuclear explosion? Of course. It’s all over the news media right now. What does that have to do with a component robot in 1290?”

“The explosion was caused by MC 5. When the component robots reach the approximate time at which they fled back into the past, with a margin of error of several days, they explode with nuclear force.”

“They do? Why?” Marcia’s dark eyes widened with horror.

“Their atoms become unstable because of a problem they did not predict. They have miniaturized themselves to microscopic size with the same device that sent them back in time. This is what made them unstable.”

“Why did they do that?”

“Apparently, they wanted to remain microscopic forever so they would not be involved with humans. They intended to avoid contact so they would not cause possible harm to people by changing the course of history.”

“Of course. The First Law of Robotics says that ‘A robot may not injure a human being, or through inaction, allow a human being to come to harm.’ “

“That’s right,” said Jane.

“And I suppose if they were masquerading as humans, they would be in danger of being given instructions by humans that they would have to obey. As I recall, the Second Law of Robotics says, ‘A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.’ “

“Show-off,” muttered Steve, rolling his eyes. “All right, give us the third one, too. Get it over with.”

Marcia arched one eyebrow at Steve and spoke in a monotone. “The Third Law of Robotics says, ‘ A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.’ Now may we get on with this briefing, please?”

“The sooner the better,” said Steve.

“I’m almost finished with this part,” said Jane. “Marcia, the new problem is that the miniaturization turned out not to be permanent. The instability of that process has caused each component robot to return to full size at a different time in history.”

“I believe I understand. At that point, of course, their interaction with humans becomes virtually inevitable.” Marcia turned to Hunter. “Is this how you decide which period in history to visit?”

“Yes,” said Hunter. “The site of the explosion in our own time reveals where to look. I made calculations from the records in the console of the time travel sphere that tell me when MC 5 was likely to return to his normal size. We must go back and try to apprehend him as soon as we can, before he influences anyone significantly. Returning him to our time with the time travel sphere will prevent him from exploding.”

“I see,” said Marcia.

“We’re almost done with this background stuff,” said Steve. “Then we can head for the Bohung Institute. Tell her about Wayne, Hunter.”

“Perhaps you can summarize that problem for us.”

“I don’t feel like it.” Steve turned away from Marcia. “I’m just the hired hand, remember? I don’t handle this theoretical stuff.”