"Well," said Norby, "that would be three of us against the villains-providing I don't have to spend all my time rescuing you two."

"There'll be some spare time for you to hide behind us, Norby," said Fargo, stroking Oola, who was lying in his lap.

"Leave Norby alone, Fargo," Jeff said. "He never hides behind anybody."

"I don't?" Norby said in a surprised tone.

"Besides," Jeff hurried on, "I have an idea. Those Mentors down there seemed very dangerous and not likely to listen to reason. But they are all very old and lots of them are dead and maybe they've deteriorated with time. After all, they were put on Jamya by the Others to teach the Jamyn how to be civilized. Why don't we go backward in time to when Jamya was first found by the Others and before they put up the force barrier? Maybe we'll speak to the young Mentors when they were healthy and reasonable."

"Hmm," murmured Fargo, "and then we'd know what the Others were like. Not a bad idea."

"I don't like it," Norby said. "The Others were probably more dangerous than the Mentors."

"Do you remember that they were?" Jeff asked.

"Well, no. I feel as though no part of me came into existence until long after the Others left, so I guess I wouldn't know anything about them."

"Are you telling us," Fargo asked, "that some of your parts are the creation of the Mentors?"

"That could be," Norby said. "I don't really know. I can't even remember what I used to be. Maybe I wasn't really a robot. Maybe I was a computer on that spaceship that McGillicuddy found. Anyway, I'm scared of the Others."

"Then we won't go back that far in time," Jeff said. "Do you think you can take us back the right amount if all of us concentrate on young Mentors?"

"Well," said Norby, "Fargo can't help, but you and I can join telepathically, and I'll try to link myself with the Hopeful, too, and we'll go back to soon after the Mentors arrived-I hope."

"Good! I'm sure the young Mentors will be reasonable," said Jeff. "Come here, Norby. Sit at the ship's computer, and I'll hold your hand."

A little wire pushed out of Norby's hat and inserted itself into the ship's computer. His hand grabbed Jeff's and held tight.

"Okay?" Norby asked.

"I'm not afraid," said Jeff. "In fact, I'm completely confident in you, Norby. If we could get back from the Ice Age smack into the Hopeful's control room, we ought to be able to move the Hopeful back into time with pinpoint accuracy."

Jeff closed his eyes so he could concentrate better-also to shut out the doubting expression on his brother's face. So what if Norby got things wrong now and then? Think of all the things he got right! Norby kept saying that, and he was right, too!

Now…concentrate on Jamya…move back…back… to a much earlier time…think of Mentors, with shiny metal, moving easily, resonant, pleasant voices.

"Jeff!" Fargo's voice was urgent. "Norby! The two of you-come out of it!"

"What…what…" Jeff came to, blearily. "What's wrong?"

"I'm not sure. You two have been still and silent for half an hour. You didn't tell me how this works, either of you. Does it take you that long to do it?"

"I don't know. Didn't anything happen?"

"Nothing at all. I had a momentary sensation of dizziness at the start, but it passed, and here we still are and there Jamya still is."

Norby was quite conscious, too, for he made a snorting noise and pulled his wire out of the computer. "Of course, we're still here and Jamya is still there, but the position of its sun is different. It's now spring in the continent where the dragons live-a long ago spring."

"You mean we've moved back in time?"

"Of course!"

"In that case," said Fargo. "Get out of my chair, little robot, and let me take us down to this planet of yours."

He put Oola on the control room floor, where she sat placidly, and licked herself like a cat while still looking like a beagle.

Down they went, skimming across the Jamyn continent.

Jeff said, "Can you find Zi's castle, Norby? You did that two times before without trouble."

"In our time, Jeff. The castle doesn't exist at this time in the past."

"I mean…Locate the place where the castle will some day exist?"

"I get no feel for it," said Norby, sounding worried.

The Hopeful skimmed low over the planetary ocean and headed back over the continent again.

"Trees. Lots of trees," Fargo said. "Those sea creatures that looked up at us might be interesting."

"No," said Norby sharply. 'The Mentors chose land creatures to civilize. Maybe we went back too far. Maybe there's no animal life on land at all."

"Not likely," Fargo said, "when it's so richly forested and vegetated. See, there's a group of animals below in the grassland." He sent the Hopeful downward in a sharply banked curve for a closer view. 'They look something like bipedal dinosaurs, but I don't see any sign of wings."

'That's odd," said Jeff. 'They don't even have them furled. I think they don't have any wings."

The Hopeful came in for a quiet landing and rested upon the grass at some distance from the herd. Fargo moved to open the airlock.

"Hey," said the ever cautious Jeff, "aren't you going to analyze the air outside?"

Fargo paused. "You've been here, haven't you? And you breathed. And you're alive."

"That was at a different time. Why don't you ask the computer?"

"Oh, well." Fargo looked pained. "What's the air like?"

The computer said, "Breathable. There are plant seeds and spores to which allergies might exist, but I can't test for that without more information."

"We'll chance it," Fargo said, as he picked up Oola.

They moved out on the grass, which was waving in the wind. It was rather cool, but Jeff remembered the glacier and decided that he could get along easily with this kind of coolness.

Jeff said, "I'll just step over there and speak to the dragons. I can speak Jamyn, you know."

"Look out!" yelled Norby, tugging at Jeff's pant legs.

The dragons were approaching en masse, and at a run. They were also speaking, but not in Jamyn. Their language, if it could be called that, consisted entirely of loud roars, screeches, and hisses, punctuated by little puffs of smoke from their nostrils.

"Jeff, old boy," said Fargo, trying to control Oola, who was snarling and barking alternately. 'These are not friends of yours. It's my opinion we had better get back into the ship at once."

Without arguing the matter, they did so, shutting the airlock behind them.

"I thought you told me that the dragons were smaller than human beings," Fargo said.

These were as big as the Hopeful. In the viewscreen, they could see the dragons swarming over the ship, trying to find a place to bite. Their fangs sounded like jackhammers upon the hull.

"Fargo," Jeff said, "I don't think their teeth are made of ivory. They look shiny, as if they were made of metal, or of diamonds."

"You're right, Jeff, and they may damage us." He moved to the controls. "We'll have to get away."

"They aren't speaking Jamyn," said Norby unnecessarily. "I don't think they've ever been civilized."

Fargo moved the Hopeful slowly upward on antigrav so that the dragons clutching at the hull gradually peeled off. The huge animals were now spouting flames in their frustration. Fargo seemed fascinated.

"From a whiff I got outside," he said, "I think they make their flames by splitting hydrogen sulfide…"

"The computer says the hull is heating under those flames," said Norby. "We should get back into orbit."

Again there was no attempt to argue the matter, and the ship rose precipitously. When it was safely in orbit, the three had another conclave, while Oola chased her tail round and round in the control room.

"My feeling is," Fargo said, "that we did get back to a time before the Others, even before the Mentors created a civilization on this planet. We went backward in time too far."