"No. No." The young man looked at them doubtfully. "Only giants are as tall as you. And the seraphim and nephilim. But you have no wings."

What was this about wings? Dennys asked, "Please, J-Jay-where are we? Where is this place?"

"The desert, about an hour from my oasis. I came out, dowsing for water." He bent down and picked up a wand of pliable wood. "Gopher wood is the best for dowsing, and I had my grandfather's-" He stopped in mid-sentence.

"Higgaion! Hig! Where are you?" he called, as the twins might have called for their dog at home. "Hig!" He looked, wide-eyed, at the twins. "If anything has happened to him, my grandfather will-there are so few of them left-" He called again urgently, "Higgaion!"

From behind the outcropping of rock came something grey and sinuous which the twins at first thought was a snake. But it was followed by a head with small, bright, black eyes, and great fans of ears, and a chunky body covered with s.h.a.ggy grey hair, and a thin little rope of a tail.

"Higgaion!" The young man was joyful. "Why didn't you come when I called you?"

With its supple trunk, the little animal, the size of a small dog or a large cat, indicated the twins.

The young man patted its head. He was so small that he did not have to bend down. "Thank El you're all right." He gestured toward the twins. "They seem friendly. They say they aren't giants, and while they are as tall as seraphim or nephilim, they don't seem to be of their kind."

Cautiously, the little animal approached Sandy, who dropped to one knee, holding out his hand for the creature to sniff. Then, tentatively, he began to scratch the hairy chest, as he would have scratched their dog at home. When the little animal relaxed under his touch, he asked j.a.pheth, "What's seraphim?"

"And nephilim," Dennys added. If they could find out what these people were who were as tall as they, it might give them some kind of a clue as to where they had landed.

"Oh, very tall," j.a.pheth said. "Like you, but different. Great wings. Much long hair. And their bodies-like you, not hairy. The seraphim are golden and the nephilim are white, whiter than sand. Your skin-it is different. Pale, and smooth, and as though you never saw sun."

"At home, it's still winter," Sandy explained. "We get very tan in the summer when we work outdoors."

"Your little animal," Dennys questioned, "looks sort of like an elephant, but what is it?"

"It's a mammoth." j.a.pheth slapped the creature affectionately.

Sandy withdrew his hand from petting Higgaion. "But mammoths are supposed to be huge!"

Dennys saw in his mind's eye a picture of a mammoth in a nature book at home, very like j.a.pheth's animal. j.a.pheth himself was a miniature version of a strong and handsome young man, not a great deal older than themselves, perhaps as old as their sister's friend Calvin, who was in graduate school. Perhaps in this place, wherever it was, everything was in miniature.

"There aren't many mammoths left," j.a.pheth explained. "I'm a good dowser, but mammoths are very fine for scenting water, and Higgaion is the best of all." He patted the little animal's head. "So I borrowed him from Grandfather Lamech, and together we found a good source of water, but I'm afraid it's too far from the oasis to be much use."

"Thank you for explaining," Sandy said, then turned to Dennys. "Do you think we're dreaming?"

"No. We came home from hockey practice. We made sandwiches. We went into the lab to find the Dutch cocoa. We messed around with Dad's experiment-in-progress. We were stupid beyond belief. But it isn't a dream."

"I'm glad to hear you say that," j.a.pheth said. "I was beginning to wonder, myself. I thought I might be dreaming, because of the stone hitting my head in the earthquake."

"It was an earthquake?" Sandy asked.

j.a.pheth nodded. "They come quite often. The seraphim tell us that things aren't settled yet."

"So maybe this is a young planet." Dennys sounded hopeful.

j.a.pheth asked, "Where have you come from, and where are you going?"

"Take me to your leader," Sandy murmured.

Dennys nudged him. "Shut up."

Sandy said, "We're from planet Earth, late twentieth century. We got here by accident, and we don't know where we're going."

"We'd like to go home," Dennys added, "but we don't know how."

"Where is home?" j.a.pheth asked.

Sandy sighed. "A long way away, I'm afraid."

j.a.pheth looked at them "You are flushed. And wet."

He himself did not seem to fee! the intense heat.

Dennys said, "We're perspiring. Profusely. I'm afraid we'll get sunstroke if we don't find shade soon."

j.a.pheth nodded. "Grandfather Lamech's tent is closest. My wife and I"-he flushed with pleasure as he said my wife-"live halfway across the oasis, by my father's tent. And I have to return Higgaion to Grandfather, anyhow.

And he's very hospitable. I'll take you to him, if you like."

"Thank you," Sandy said.

"We'd like to come with you," Dennys added.

"At this point, we don't have much choice," Sandy murmured.'

Dennys nudged him, then took his turtleneck from the bundle of clothes and pulled it back on, his head emerging from the rolled cotton neck, which had mussed up his light brown hair so that a tuft stuck out like a parakeet's. "We'd better cover ourselves. I think I'm sunburned al-ready."

"Let's go, then," j.a.pheth said. "I'd like to be home before dark."

"Hey-" Sandy said suddenly. "At least we speak the same language. Everything's been so wild and weird I hadn't realized it till-"

j.a.pheth looked at him in a puzzled manner. "You sound very strange to me. But I can understand you, if I listen with my under-hearing. You talk a little like the seraphim and the nephilim. You can understand me?"

The twins looked at each other. Sandy said, "I hadn't really thought about it till now. If I think about it, you do sound, well, different, but I can understand you. Right, Den?"

"Right," Dennys agreed. "Except it was easier when we weren't thinking about it."

"Come on," j.a.pheth urged. "Let's go." He looked at Sandy. "You'd better cover yourself, too."

Sandy followed Dennys's example and pulled on his turtleneck.

Dennys unrolled his flannel shirt and draped it over his head. "Sort of like a burnoose to keep us from getting sunstroke."

"Good idea." Sandy did the same.

"If," Dennys added morosely, "it isn't already too late." Then he said. "Hey, j.a.ph-" stumbled over the name-"Hey, Jay, what's that?"

On the horizon to the far left, moving toward them, appeared a creature which shimmered in and out of their vision, silvery in color, as large as a goat or a pony, with light flickering out from its forehead.

Sandy also shortened j.a.pheth's name. "What's that, Jay?" The mammoth pushed its head under Sandy's hand and he began to scratch between the great fan-like ears.

j.a.pheth looked toward the barely visible creature, smiling in recognition. "Oh, that's a unicorn. They're very odd. Sometimes they are, and sometimes they aren't. If we want one, we call and it'll usually appear."

"Did you call on one?" Sandy asked.

"Higgaion may have thought about one, but he didn't really call it. That's why it isn't all the way solid. Unicorns are even better about scenting for water than mammoths, except that you can't always count on them. But probably Higgaion thought one might be able to confirm where we thought there was a spring." He smiled ruefully. "Grandfather always knows what Hig is thinking, and I make guesses."

The twins stopped and looked at each other, but the mammoth had left Sandy and was trotting after j.a.pheth, who was walking toward the oasis again, so they followed. In the intensity of the desert heat, their limbs felt heavy and uncooperative. When they looked to where the unicorn had been, it was no longer there, though there was left in its place a mirage-like shimmering.

Sandy panted. "I don't believe this."

Dennys, jogging beside him, agreed. "We've never had very willing suspensions of disbelief. We're the pragmatists of the family."

"I still don't believe it," Sandy said. "It I blink often enough, we'll be back in the kitchen at home."

Dennys took one of the flapping sleeves of his shirt and wiped his eyes. "What I believe right now is that I'm hot. Hot. Hot."

j.a.pheth turned his head and looked back. "Giants! Come on. Stop talking."

With their long legs, it was easy enough for the twins to catch up with j.a.pheth- "We're not giants," Dennys reiterated. "My name is Dennys."

"Dennysim."

Dennys touched his forehead, as j.a.pheth had done.

"One Dennys. Me."

Sandy, too, touched his forehead. "I'm Sandy."

"Sand." j.a.pheth looked around. "We have plenty of Sand."

"No, Jay," Sandy corrected. "It's short for Alexander. Sandy."

j.a.pheth shook his head. "You call me Jay. I call you Sand. Sand is something I understand."

"Talking of strange names"-Dennys looked at the mammoth, who was again b.u.t.ting at Sandy, to be petted.

"Hig-"

"Hig-gai-on." j.a.pheth sounded it out.

"Are all mammoths his size? Or are there some really big ones?"

j.a.pheth looked puzzled. "Those that are left are like Higgaion."

Sandy looked at his brother. "Didn't horses start out very little, back in pre-history?"

But Dennys was looking at the horizon. "Look. Now you can see that there are lots of palm trees."

Although they could now see that there were many trees, the oasis was still far away. Despite their much longer legs, the boys began to lag behind j.a.pheth and the mammoth, who were moving across the sand at an easy run.

"I'm not sure I can make it," Dennys said, grunting.

Sandy's steps, too, lagged. "I thought we were the great athletes," he said, panting.

"We've never been exposed to heat like this before."

j.a.pheth, evidently realizing that they were no longer behind him, turned around and jogged back toward them, seemingly cool and unwinded. "What's the matter? You're both all red. The same red. You truly are two people?"

"We're twins." Sandy's voice was an exhausted croak.

Dennys panted. "I think-we're getting-heat-heat prostration."

j.a.pheth looked at them anxiously. "Sun-sickness can be dangerous." He reached up and touched Dennys's cheek. Shook his head. "You're cold and clammy. Bad sign." He put his hand against his forehead. Appeared to be thinking deeply. Then: "What about a unicorn?"

"What about it?" Sandy asked. He felt tired and irritable.

"If we could get a couple of unicorns to become real and solid for us, they could carry you to the oasis."

The twins looked at each other, each seeing a red, sweating mirror version of himself. "We've never gone in for mythical beasts," Dennys said.

Sandy added, "Meg says unicorns have been ruined by overpopularity."

j.a.pheth frowned. "I don't understand what you're saying."

Dennys, too. frowned. Thinking. Then: "Jay's unicorns sound more like Mother's virtual particles than like mythical beasts."

Sandy was exasperated. "Virtual particles aren't mythical. They're theoretical."

Dennys shot back, "If Mother can believe in her way-out theories, we ought to be able to believe in virtual unicorns."

"What kind of unicorns?" j.a.pheth looked puzzled. "Is it because you're some strange kind of giant that there's all this confusion?" !"

"Unicorns have never been a matter of particular importance before." Sandy wiped his hands across his face and was surprised to find that the beads of sweat were indeed cold.

"They're important now." Dennys groaned. "Mother believes in virtual particles, so there's no reason there can't be virtual unicorns."

"Hig-"j.a.pheth urged.

The mammoth turned and faced the horizon. A faint shimmering glimmered on the sand in front of him. Slowly it took the shape of a unicorn, transparent but recognizable. Beside it, another unicorn began to shimmer.

"Please, unicorns," Dennys begged. "Be real."

Slowly the transparency of both creatures began to solidify, until there were two unicorns standing on the sand, with silvery-grey flanks, silver manes and beards. Silver hooves, and horns of brilliant light. They looked at the twins and docilely folded their legs under to lie down.

"Oh!" j.a.pheth exclaimed. "It's a good thing you're both so young. For the moment, I'd forgotten that unicorns will not let themselves be touched by anyone who is not a virgin."

The twins glanced at each other. "Well, we don't even have our driver's licenses yet." Dennys said.