Radiation, a new and exotic phenomena for much of the twentieth century, was seized on by writers as a pretext for all manner of unlikely but exciting developments, everything from giant monsters to Spider-Man Spider-Man. Zombies too, of course: In Night of the Living Dead Night of the Living Dead, it's suggested that the recently deceased are brought back as zombies due to strange radiation from a pa.s.sing comet.

The idea of extraterrestrial influence being responsible for an exponentially expanding plague that transforms ordinary people into a sinister menace is an old one in science fiction. Perhaps the best known example is Jack Finney's 1954 novel The Body s.n.a.t.c.hers The Body s.n.a.t.c.hers, filmed in 1956 as Invasion of the Body s.n.a.t.c.hers Invasion of the Body s.n.a.t.c.hers (and remade several times since), in which lurking alien seed pods grow perfect simulacra of your friends and neighbors, and the impersonators then proceed to murder and replace the originals. Another well-known example is Robert Heinlein's 1951 novel (and remade several times since), in which lurking alien seed pods grow perfect simulacra of your friends and neighbors, and the impersonators then proceed to murder and replace the originals. Another well-known example is Robert Heinlein's 1951 novel The Puppet Masters The Puppet Masters, about sluglike aliens that attach themselves to the backs of human hosts and take control of them. (The novel, which taps into the anti-Communist hysteria of the time, makes explicit a.n.a.logies between the alien menace and the Soviet Union.) For whatever reason, zombie stories of recent decades have tended to eschew cosmic explanations and have typically blamed zombies on man-made superviruses or else just left the question open. Our next story harkens back to this grand old tradition of zombies from outer s.p.a.ce, and reminds us that we should never, ever forget to watch the skies.

When the rapeworms began to rain from the Ohio skies, I tossed my two boys in the truck with cases of canned food and all our camping gear, and we headed south for the Hocking Hills, far away from Columbus and the other big cities.

Too many other folks had the same idea. We found a small colony in and around Old Man's Cave, cl.u.s.ters of tents spilling down the gorge from the shelter of the cave all the way to the Devil's Bathtub. There were men and women both, which was just plain stupid with the rains coming this far north. Some folks were hostile, but a couple of college kids offered to help us pitch camp.

Josh hung back at my elbow, fidgeting. When the college kids weren't looking, he b.u.mped into me and whispered, "Dad, we have to get farther away than this."

I looked down at his face, and saw the way he was trying to look mean and strong, and I hoped he wasn't imitating me. He was only thirteen, and his face still had a few soft edges to it.

"Don't be scared," I said.

"I'm not scared."

"Neither am I," I lied. "It's safe out here."

"No, it's not."

Josh was a news junkie, had been falling asleep at night with CNN, ever since the s.p.a.ceship-or whatever it was-pa.s.sed over Earth and the rapeworms started. At first the scientists thought it was a killer asteroid aimed at the planet. Maybe it would have been better for us all if it had been.

"Hey," one of the college kids yelled. "You can leave the kids here, go get your stuff from the car."

Nick, my nine-year-old, tugged frantically at my sleeve, his chin trembling. He talked through clenched teeth, punctuating each word with an angry pause. "Don't. Leave. Us. Here."

I put my arm around him and pulled him close, but he struggled against my grip. "I won't do that. I promise we'll stay together. We'll be okay."

So I told the college kids we'd just go up to the car together so the boys could help me carry stuff. Then when we got to the parking lot, we ran to the car and headed east on Route 56 toward Lake Hope State Park.

It was getting dark. When I first saw the man in the plaid flannel jacket on the side of the road, I figured him for another refugee. But then he saw us, and lurched out into the path of the car waving his arms for us to stop. By the way he moved, all stiff and jerky, I could tell that he was infected.

"Get down," I yelled at the boys. "Get down!"

I tried to steer around him, but he moved fast, if awkwardly. I had a brief nightmare of him flying through the windshield like a deer, because that would be it for us then. But I twisted the wheel at the last second, clipping him with the b.u.mper, and he flew off the side of the road while I held onto the wheel and controlled the car.

"What was that? What was that?" Nick yelled.

Josh's voice was calmer. "Did you hit him? Is he gone? Dad, did you hit him?" Dad, did you hit him?"

"Don't worry! Settle down!" I yelled. Fighting every natural instinct in my body to pull off to the side of the road, I put my foot down and hit the gas. "It's all right. Everything's all right."

Less than a mile up the road, I saw a car crashed into a ditch, which made me wonder: What if that man wasn't infected? What if he was just an accident victim, injured, looking for help? I pushed those questions out of my mind; I had to a.s.sume he was infected.

When I came to the Lake Hope sign, I drove past it.

Soon enough, we were on a dark, unpopulated road that led through the Wayne National Forest. If we stayed on it, we'd end up in the university town of Athens, where there were too many people. So when I saw a gate for an old logging trail into the forest, I pulled over and broke the chain on it with the tire iron. After driving the car through, I closed the gate again and poked through my toolbox for a spare lock to close the gate again. Sure, somebody else might come along and break it later, but there was no need to advertise we were here.

If I'd been thinking ahead, I would have driven all night. South toward Ironton, there were places in the woods as far away from people as we were likely to get anywhere in Ohio, and the rapeworms were unlikely to spread north into the upper peninsula of Michigan. But it was November, already after seven at night, and in the dark you can't see the rapeworms falling.

Nick was at the frazzled end of his nerves, whining and sucking his thumb, something he hadn't done since kindergarten. I just wanted to be someplace, anyplace. So we found a clearing, out of sight of the road, and we set up camp. Josh seemed glad to have some work to do. He practically put up the whole tent by himself while I talked to Nick and tried to get him to calm down.

Well after midnight, when I thought they were both asleep in their thermal sleeping bags, I tiptoed back out to the truck to listen to the radio. There were still stations broadcasting from some of the cities in the north. I sat there shivering, scanning the AM radio channels in hopes of any helpful news.

WTVN out of Columbus was dead, but I was able to pick up WJR out of Detroit. s.n.a.t.c.hes of news came in through the static.

"...scientists are still trying to understand the alien biology of the parasite infection that is sweeping the globe..."

"...officials report that the nuclear device exploded over Orlando, Florida, has sterilized the threat there, and will prevent the spread of further contamination..."

"...meanwhile in Ohio, the governor has extended martial law to the highways. All personal travel is forbidden as long as the crisis lasts. Cars on the highway may be shot without warning..."

When that signal faded, I tried a Cleveland station with no luck. I could pick up a couple Christian stations out of West Virginia, but I couldn't stomach their message. If we survived, if I saved my kids, then it wasn't the end of the world.

I was lost in these thoughts, watching the breath frost from my nose, when a tap at the window made me jump, and I jerked up my gun and aimed it at my attacker.

It was Nick. He was standing there without his coat on, bawling.

I started sobbing even before I opened the door and gathered him into my arms. I rocked him and told him how sorry I was. Snot ran from my nose while static poured out of the tinny speakers.

After a few moments, we both stopped crying. He snuggled down into my arms. "What are you doing?" he asked.

"I'm listening to music."

I reached out and hit the scan b.u.t.ton, looking for something to distract him, but we only caught s.n.a.t.c.hes of news, mostly from the Christian stations in small towns still unaffected by the plague.

"...the fifth angel sounded, and I saw a star from heaven fallen unto the earth: and there was given to him the key of the pit of the abyss..."

"...and the rest of mankind, who were not killed with these plagues, repented not of the works of their hands..."

"...hallelujah! Salva-"

I punched it off. Then I turned off the car, to save the battery and the gas. I started to sing to him, "Bye, bye, Miss American Pie, drove my Chevy to the Levee-"

"Dad, that's an old song. It's so lame."

"I'm glad you're here," I said, tousling his hair.

"Why couldn't we bring Schrody?"

"Schrody's a smart cat. He can look out for himself."

"But who's going to change his litter box?"

I hugged him close, looking through the window as the dashboard light faded. The trees formed a black wall around us, like the sides of a pit, and the darkness of the sky made the stars seem to twitch like maggots. "We get to camp out and pretend we're Indians. Won't that be fun?"

"Where's Mom? Is Mom safe?"

I checked my cellphone to see if my ex had called, but the battery was dead and I had forgotten to pack the dashboard charger. Their mother and I had gone through a bitter divorce, which we tried to keep from the boys, even though we split custody. Tomorrow was the usual day I turned them back to her. She would be frantic with worry when she didn't hear from us, but I convinced myself it was better to have no contact until the plague pa.s.sed. The government had censored pictures of what happened to women infected by the rapeworm, but we heard rumors.

"Yeah, she's safe," I promised. "She wants me to tell you that she misses you."

His eyes brightened for a second, then he sank back down into my arms. "You don't really know."

I held him until he fell back to sleep. He started to wake up every time I tried to put him down or move him, so I leaned the seat back and fell asleep myself.

When I woke up in the morning, the windows were frosted over with ice, and the sun coming through them was bright and harsh. Josh was in the car too, in the pa.s.senger seat, curled up with his head against my arm.

They both looked untroubled in their sleep, the way they always had until just a few months before. I knew I would do whatever I had to do to keep them safe.

After we woke up, I checked our supplies. We had our fishing gear, and I had my grandfather's old single barrel shotgun in the trunk, with a couple boxes of sh.e.l.ls. There was also his old .38 Special revolver, the one he bought to protect his store and then never needed. I had just the rounds inside that, and no extras. I didn't like guns, and wouldn't have owned these if I hadn't inherited them.

I checked out our supply of canned foods. If we were careful, we could get through the next few weeks until things settled down.

"Dad, you know what we forgot to pack?" Josh said while we ate canned pears for breakfast.

I picked up the can opener where he'd left it on the ground, and put it back in my kit. "No, what?"

"Twinkies. They're the perfect food. They never go stale. They survive anything."

I grinned, and he flashed a smile back. For a moment, I thought everything would be okay. "I think it's better if we have healthier food," I said.

"I thought you said we were going to have fun," he said.

The way he said it threw the lie back in my face. But I grinned anyway.

Over the next few weeks, Josh and I ate canned food until the green beans tasted like the corn like the peaches like the ham. Nick ate only peanut b.u.t.ter, until all the peanut b.u.t.ter was gone. The three of us sat inside the tent, playing Uno until the day Nick tore all the cards in half because we were out of peanut b.u.t.ter. We were cold all the time and we started to stink, spending day after day in the tent, until Josh started holding his nose shut every time he sat next to me. I didn't pack enough toilet paper, and I screamed at the boys when they used the last roll of it to clean up spilled peaches.

We moved camp twice. The first week, we heard cars roaring by on the nearby roads, so we moved to a clearing farther back in the woods. A week later there were days of planes flying overhead-fighter jets and helicopters-so we moved farther back under the trees. We spent our days watching the skies, staring at the roads, jumping every time a squirrel crunched through the leaves, dashing out our fire any time we heard something like a gunshot.

At night, when the boys were sleeping, I listened to the radio for news. Scientists still hadn't found a way to remove the rapeworms from brain tissue without killing the patients. We were no longer in touch with the rest of the world: the Middle East was the first to go completely silent. Americans were moving north across the border into Canada.

I thought about following with the boys, but the gas gauge in the car read empty after I fell asleep one too many times listening to the radio with the engine running.

It was the second week of December when I took the shotgun out to try for a deer, telling the boys they had to stay in the tent until I came back. I was a half mile away when I heard an explosion, and then another, something far away but powerful enough to make the ground shake. I ran all the way back to our camp, and the boys were running out to meet me, and we all waited together for something else to happen.

Snow fell that night, the first snowfall of the year that was more than just flurries, three or four inches of it before morning. There was a glow on two horizons, west toward Cincinnati and north toward Columbus, and the fresh snowfall caught the light and spread it everywhere.

Nick had the leftover peanut b.u.t.ter jars, which he had filled full of acorns he collected in the woods. He sat there, shaking them louder and louder, like some kind of shaman trying to ward off evil, until I snapped at him, and told him to be quiet, I just needed some quiet to think.

Before we curled up in our blankets that night, I told the boys to hold my hands. We sat there silently, but I prayed that we would make it. All we had to do was lay low and survive long enough, and my boys would have a chance.

It was in the morning, when we went outside, that we saw the footprints in the snow.

Josh spotted the tracks first when he left the tent to pee. I heard him running back, feet crunching through the snow. He yanked open the tent flap in a panic. "Dad, you gotta see this. Somebody's been watching us."

We all three went. I carried Nick, if only to keep him from hanging onto my legs and tripping me. He growled and bit my shoulder and pounded on me with his fists.

"Look, they're the same size as mine," Josh said. "It's just another kid. Maybe he's out here all by himself."

Nick squirmed out of my arms at that point, eager to take a look himself.

Together, we trudged through the snow, following the straight line of the trail through the woods. When we came to the road, I realized how stupid I'd been.

"Don't move," I whispered to the boys. And then stepping over to a pine tree, I reached inside and broke off several branches, using them to try to cover up my tracks as I retraced them.

Nick fidgeted, shifting from foot to foot, kicking up the snow, but Josh wore a look of horror. "If we can follow them, anyone who comes by here could follow us."

I nodded. "We'll go back to camp, stepping in the same footprints as we go, okay? We'll use the branches to cover our steps."

"What about the other boy?" Nick asked as I scooped him up in my arms.

"What?"

"Yeah," Josh said. "He's probably really scared out here."

"You can't leave him out here, Dad."

I d.a.m.n well could, I thought, but then I saw their faces. If the boy was infected, he would have walked straight into our camp.

"Okay," I said. "But you two have to stay here. You can hide inside this pine tree, and watch me go."

I thought that would be the breaking point, that Nick would change his mind, but he scrambled through the branches, spilling snow, as soon as I put him down. "I'll take care of him," Josh said.

I crossed the road, brushing away both sets of prints as I went. I figured to take a quick look around, then report back to the boys that I couldn't find anything. We'd move our camp again, and this time I would keep a better eye out for other people.

But I was only ten or twenty feet off the road when I saw a splash of camouflage, bright green against the snow, amid a flash of movement.

"Hey, come back!" I called.

I ran after the kid-it was definitely a kid-without bothering to cover my tracks. I came into a small clearing, and saw him standing on the other side, half-hidden by a tree.

"It's okay," I said. "I'm not going to hurt you."

"Baby?"