Norby said, "I'm sure, somehow, that this hassock opens up if you figure out the mental key encoded in the squiggles around its sides. Something's inside."

"What?"

"I don't know. But don't keep talking, Jeff. Those little attack robots are almost down the hill. "

Norby activated his antigrav and sailed under Jeff's other arm, the one that wasn't holding the hassock. "Ready?" he asked.

The oncoming crablike robots scurried faster.:'Put down what you are holding and surrender yourselves. You are our prisoners," they cried out in chorus, their squeaky voices painfully shrill.

"No," said Jeff. "You have a nice planet but you don't know how to make visitors feel at home. Now, good-bye."

"Wait, don't go," they all squeaked.

Jeff said, "Straight back to our apartment, Norby. The security police will be gone by now. Make sure your protective shield reaches around the hassock while we're in hyperspace, and don't think about our home coordinates very hard. I don't want the Mentor to know."

"Don't worry," said Norby. "I don't think he's strong enough to use telepathy without the help of his main computer, or without touching us."

The attack robots were almost upon them. "Let's go, Norby!"

The grayness came and went-and they were falling. "Norby," shouted Jeff, "turn on your antigrav before we hit!"

They zoomed upward and Jeff, trembling a little, looked down. He was still holding the hassock under his left arm, and Norby under his right, and they were no longer on Jamya. That was clear.

But they weren't in the Wells' apartment either. There was no apartment, no building, no Manhattan. Only a vast whiteness stretched below them.

"Snow?" said Norby. "It's summer. What's snow doing here?"

"That's not just snow," Jeff said. "That's a glacier."

"You've brought us to Alaska!" Jeff was shivering. "Or some such place far north! Or someplace far south, like Antarctica. Or maybe even to some other planet."

"This is Earth. I'm certain of it," Norby said as they skimmed above the ice. "The coordinates check, and I'm sure that's Earth's sun. I guess it's Antarctica."

"No, it isn't," Jeff said. "If that's Earth's sun, it's quite high in the sky, so it can't be Antarctica. Or Alaska, either. I'd say it was the Tibetan plateau, except we'd be able to see mountains, and we don't."

"Don't get all excited, Jeff. Here come some horses, and maybe we can ask the riders…"

Jeff squinted in the direction Norby was pointing. "There aren't any riders, and those are camels. Big, shaggy camels, and they're walking over snow! Uh, oh!"

Norby's pair of eyes facing Jeff closed suddenly and then popped open "You think…"

"Yes, I think! Which you don't." Jeff studied the circle of the horizon. What had seemed to be solid whiteness resolved itself into a slope, and in the south-if it was south-there was a valley with stunted pine trees beginning where the glacier ended. The valley went on and on, deeper and deeper, and way out was the Atlantic. Or was it the Pacific?

"Norby! There's another herd of animals over there by those pine trees. Take us closer!"

It was worse than Jeff had imagined. "Do you know what those animals are?" he demanded.

"Elephants," quavered Norby, "and they shouldn't be up in the snow country, should they?"

"It's worse than elephants. Those elephants are extinct elephants."

"But they're alive."

"They're alive now, but they're going to be extinct some day. Look at them, Norby! Elephants don't have long blond hair. They're mastodons, and we're seeing them with our own eyes, which no one else of our generation has ever done."

"Maybe they're woolly mammoths. Aren't woolly mammoths supposed to live in cold climates?"

"Not any more. Not since the last Ice Age-which is where you've taken us to."

"I'm sorry, Jeff. I really am. I was thinking so much about time travel that I automatically did it when I was just trying to get us home."

"You said you didn't know how."

"I don't, but something inside me…"

"Oh, never mind," Jeff said. "Anyway, mammoths had large round bulges on top of their heads and mastodons didn't. Mastodon bones were found up the Hudson River Valley in the eighteenth century."

Jeff paused. Then he said thoughtfully, "Well, then, this is the Hudson River Valley, or what will become the Hudson River Valley once the glacier retreats. Over there is the prehistoric Hudson canyon with a river carrying melted glacier water to the sea, and it will be covered by ocean in our own time. This could even be before the Indians entered the Americas. Norby, you've got to take us to our own century." The hassock was getting awkward to hold in the cold, and Jeff tried to balance it on his hip. He wished he could put his hands in his pockets because it was so cold.

"Jeff," Norby said, "I'm too scared to try. I muddle things. Maybe we should just stay here."

"In this Ice Age? We'll surely freeze to death. And if we go south to where it's warm, we'll still have nothing to eat, no weapons for catching game, and nobody to talk to but each other. Besides, I want to be back in my own time."

"But I don't know how to get back!"

"You got back from the Roman Coliseum."

"Well, when the lion jumped on me, I got so scared that I stopped thinking. I just time jumped."

"Then do it again now."

"I can't stop thinking."

It's my responsibility, thought Jeff. Norby is just a mixed-up little robot with talents he doesn't understand or know how to use very well. It's no use blaming him or trying to make him solve the problem. I've got to do it. Fargo always says "Don't think a lot, little brother, just think smart, and when you decide to act, do it with all your heart:' He was still having trouble with the awkwardly shaped hassock. He couldn't get a comfortable grip on it with his chilled fingers. -How do I think smart? he wondered.

— I don't understand you, Norby interjected. Then he remembered. Ever since the dragon bite, he and Norby had been able to telepathize when they were in contact and thinking hard. He said, "I was just trying to think, Norby, and you're reading my mind."

"I wish you could read my mind and tell me how to get back to our own time. I can do it, but I can't seem to make myself. Maybe it isn't part of either the alien me or the Terran me, but from the two being mixed together."

There was silence for a while, during which Jeff could feel himself shivering and hear his teeth chattering. Finally he said" All I can hear in your mind is 'Oh, my, Jeff will sell me if I keep being so mixed up.' Now, just stop that, because I'm not going to sell you. You're my robot forever, mixed up or not."

"Thank you, Jeff," said Norby. "And all I can hear in your brain is 'I'm so cold. I'm so cold.' I feel terrible about that, Jeff."

"Well," said Jeff miserably, "at least it's summer here, or the sun wouldn't be so high in the sky, and it's a clear afternoon, with no wind blowing. It's cold enough, but it could be lots colder another day or another season. Let's try together, Norby. I'll think hard about our apartment. You tune into that image in my head and then perhaps you'll find the time coordinates maybe by reflex."

They tried and failed.

"It doesn't work!" Norby wailed.

Jeff bit his lip and tried not to feel despair. There had to be some way out. "Norby," he said, "maybe we're not trying hard enough because we don't really want to go back to the apartment, and it might not be safe. If we could go to our family scoutship, the Hopeful, that might make more sense, only…"

"Only what?"

"Well, I'm not sure where it is. It could be at the big dock that orbits Mars along with Space Command-now that Fargo is part of Admiral Yobo's team. but there are thousands of berths there, and I don't know which one would be Hopeful's. In fact, I can't be absolutely sure the scoutship is even there."