The Prof, as he insisted they call him, opened a little sack on his belt and offered the boys a taste of dried figs.

As the last embers of daylight faded and the stars began to come out, he suggested, “Why don’t you come to my place for the night? It’s better than sleeping out in the open.”

Hawk didn’t reply, thinking it over.

“There’s wild boars in the woods, you know,” said the Prof. “Mean beasts. And the cats hunt at night, too. Coyotes, of course. No wolves, though; for some reason they haven’t made it to this island.”

“Where’s your cabin?” Hawk asked. “Who else lives there?”

“Ten minutes’ walk,” the Prof answered, pointing with an outstretched arm. “And I live alone. There’s nobody but me on this island—except you, of course.”

The old man led the way through the trees, guiding the boys with a small greenish lamp that he claimed was made from fireflies’ innards. It was fully dark by the time they reached the Prof’s cabin. To Tim, what little he could make out of it looked more like a bare little hump of dirt than a regular cabin.

The Prof stepped down into a sort of hollow and pushed open a creaking door. In the ghostly green light from his little lamp, the boys stepped inside. The door groaned and closed again.

And suddenly the room was brightly lit, so bright it made Tim squeeze his eyes shut for a moment. He heard Hawk gasp with surprise.

“Ah, I forgot,” the Prof said. “You’re not accustomed to electricity.”

The place was a wonder. It was mostly underground, but there were lights that made everything look like it was daytime. And there were lots of rooms; the place just seemed to go on and on.

“Nothing much else to do for the past two centuries,” the Prof said. “Home improvement was always a hobby of mine, even back before the Flood.”

“You remember before the Flood?” Tim asked, awed.

The Prof sank his chunky body onto a sagging, tatty sofa and gestured to chairs for the boys to sit on.

“I was going to be one of the Immortals,” he said, his rasping voice somewhere between sad and sore. “Got my telomerase shots. I’d never age—so long as I took the booster shots every fifty years.”

Tim glanced at Hawk, who looked just as puzzled as he himself felt.

“But then the Flood wiped all that out. I’m aging again . . . slowly, I grant you, but just take a look at me! Hardly immortal, right?”

Hawk pointed to the thickly stacked shelves lining the room’s walls. “Are all those things books?”

The Prof nodded. “My other hobby was looting libraries—while they were still on dry land.”

He babbled on about solar panels and superconducting batteries and thermoionic generators and all kinds of other weird stuff that started to make Tim’s head spin. It was like the Prof was so glad to have somebody to talk to he didn’t know when to stop.

Tim had always been taught to be respectful of his elders; sometimes the lessons had included a sound thrashing. But no matter how respectfully he tried to pay attention to the Prof’s rambling, barely understandable monologue, he kept drifting toward sleep. Back home everybody was abed shortly after nightfall, but now this Prof was yakking on and on. It must be pretty near midnight, Tim thought. He could hardly keep his eyes open. He nodded off, woke himself with a start, and tried as hard as he could to stay awake.

“But look at me,” the Prof said at last. “I’m keeping you two from a good night’s sleep, talking away like this.”

He led the boys to another room that had real beds in it. “Be careful how you get on them,” he warned. “Nobody’s slept in those antiques in fifty years or more, not since a family of pilgrims got blown off their course for New Nashville. Stayed for damned near a month. Ate me out of house and home, just about, but I was still sad to see them go. I . . .”

Hawk yawned noisily and the Prof’s monologue petered out. “I’ll see you in the morning. Have a good sleep.”

Tim didn’t care about the Prof’s warning. He was so sleepy he threw himself on the bare mattress of the nearer bed. He raised a cloud of dust, but after one cough he fell sound asleep.

Because the Prof’s home was mostly underground it stayed dark long after sunrise. Tim and Hawk slept longer than they ever had at home. Only the sound of the Prof knocking hard on their bedroom door woke them.

The boys washed and relieved themselves in a privy that was built right into the house, in a separate little room of its own, with running water at the turn of a handle.

“Gravity feed,” the Prof told them over a hearty breakfast of eggs and ham and waffles and muffins and fruit preserves. “Got a cistern for rainwater up in the hills and pipes carry the water here. I boil all the drinking and cooking water, of course.”

“Of course,” Hawk mumbled, his mouth full of blueberry muffin.

“We’ve got to haul your boat farther up out of the water,” the Prof said, “and tie it down good and tight. Big blow likely soon.”

Tim glanced out the narrow slit of the kitchen’s only window and saw that it was dull gray outside, cloudy.

Once they finished breakfast, the Prof took them to still another room. This one had desks and strange-looking boxes sitting on them, with windows in them.

The Prof slipped into a little chair that creaked under his weight and started pecking with his fingers on a board full of buttons. The window on the box atop the desk lit up and suddenly showed a picture.

Tim jerked back a step, surprised. Even Hawk looked wide-eyed, his mouth hanging open.

“Not many weather satellites still functioning,” the Prof muttered, as much to himself as the boys. “Only the old military birds left; rugged little buggers. Hardened, you know. But even with solar power and gyro stabilization, after two hundred years they’re crapping out, one by one.”

“What is that?” Hawk asked, his voice strangely small and hollow. Tim knew what was going through his friend’s mind: This is witchcraft!

The Prof launched into an explanation that meant practically nothing to the boys. Near as Tim could figure it, the old man was saying there was a machine hanging in the air like a circling hawk or buzzard, but miles and miles and higher, so high they couldn’t see it. And the machine had some sort of eyes on it and this box on the Prof’s desk was showing what those eyes saw.

It didn’t sound like witchcraft, the way the Prof explained it. He made it sound just as natural as chopping wood.

“That’s the United States,” the Prof said, tapping the glass that covered the picture. “Or what’s left of it.”

Tim saw mostly wide stretches of blue stuff that sort of looked like water, with plenty of smears of white and gray. Clouds?

“Florida’s gone, of course,” the Prof muttered. “Most of the Midwest has been inundated. New England . . . Maryland and the whole Chesapeake region . . . all flooded.”

His voice had gone low and soft, as if he was about to cry. Tim even thought he saw a tear glint in one of the old man’s eyes, though it was hard to tell, under those shaggy white brows of his.

“Here’s where we are,” the Prof said, pointing to one of the gray smudges. “Can’t see the island, of course; we’re beneath the cloud cover.”

Tim looked at Hawk, who shrugged. Couldn’t figure out if the Prof was crazy or a witch or what.

The Prof tapped at the buttons on the oblong board in front of him and the picture on the box changed. Now it showed something that was mostly white. Lots of clouds, still, but they were almost all white and if that was supposed to be ground underneath them the ground was all white, too.

“Canada,” said the Prof, grimly. “The ice cap is advancing fast.”

“What’s that mean?” Hawk asked.

The Prof sucked in a big sigh and looked up at the boys. “It’s going to get colder. A lot colder.”

“Winter’s comin’ already?” Tim asked. It was still springtime, he knew. Summer was coming, not winter.

But the Prof answered, “A long winter, son. A winter that lasts thousands of years. An ice age.”