Never forget, Sams. Love is forever. If it wasn't, it wouldn't be love. The world is beautiful. If it wasn't, it wouldn't be the world.

The wildest thing about holding my brother's memories inside me? Seeing myself through his eyes, hearing myself with his ears, sailing the Cassiopeian sea in three dimensions, the way we experience practically everything except the one thing we're supposed to understand the best: ourselves. To Sam, there is the bundle of colors and smells and sensations that make up Cassie, and that Cassie is not Ben's Cassie or Marika's Cassie or Evan's Cassie or even Cassie's Cassie; she belongs to Sam and to Sam alone.

The pod rolls, the shining blue gem slips from sight, and for the last time in my life I am afraid, as if I've fallen off the edge of the world-which I guess in a sense I have. Instinctively, I reach for the vanished Earth; my fingertips bump against the window.

Good-bye.

Oh, I am too far away. And too close. There I am, hearing a tiny voice scratching in the wilderness, Alone, alone, alone, Cassie, you're alone. And there I am looking through Evan's eyes at the girl with the indispensable teddy bear and the useless M16, huddled in her sleeping bag deep in the woods, thinking she's the last person on Earth. I watch her night after night and go through her things while she's away foraging. What a bastard I am, touching her stuff and reading her journals, why can't I just kill her already?

That's my name. Cassie for Cassiopeia. Alone as the stars and lonely as the stars.

Now I discover myself in him and I am not the person I expected to find. His Cassie sears the darkness with the brightness of a billion suns. He's as baffled by this as I am, as humanity is, as the Others are. He can't say why. There's no reason, no neat explanation. It's impossible to understand and impossibly irrelevant, like asking why anything exists in the first place.

He had the answer, all right. It just wasn't the answer I was looking for.

I'm sorry, Evan; I was wrong. It wasn't the idea of me that you loved, I know that now. The stars outside the window fade, overtaken by that nauseating green glow, and after a minute the hull of the mothership slides into view.

Oh, you bitch. For a year, I've hated your green guts. I've watched you, filled with hate and fear, and now here we are, just the two of us, Other and humanity.

That's my name. Not Cassie for Cassandra. Or Cassie for Cassidy. And it's not Cassie for Cassiopeia. Not anymore. I am more than her now.

I am all of them, Evan and Ben and Marika and Megan and Sam. I am Dumbo and Poundcake and Teacup. I am all the ones you emptied, the ones you corrupted, the ones you discarded, the thousands you thought you had killed, but who live on in me.

But I am even more than this. I am all those they remember, the ones they loved, everyone they knew, and everyone they only heard about. How many are contained in me? Count the stars. Go on, number the grains of sand. That's me.

I am humanity.

ZOMBIE.

WE MOVE TO the cover of the trees. If what I suspect has actually happened-that someone inside the base has zapped everyone else-there's not much risk in bringing them with me, but there's some risk, and somebody who should know once told me it's all about the risk.

Nugget is furious. Megan seems relieved.

"Who's gonna watch her if you come with me?" I ask him.

"I don't care!"

"Well, one of us does. And that person happens to be in charge."

Through the woods and into the no-man's-land boundary that runs the perimeter of the base, toward the closest entrance and the watchtower beside it. I have no weapon, no means to defend myself. An easy target. No choice, though. I keep walking.

I'm soaked to my bones, and the temperature hovers in the midforties, but I am not cold. I feel great; even my leg doesn't hurt anymore.

CASSIOPEIA.

THE GLISTENING GREEN SKIN of the ship fills the window, blotting out the stars. It's all I can see now, and the light from the sun sparks off its featureless surface. How big did they say it was? Twenty-five miles from tip to tip, roughly the size of Manhattan. I'm seeing only a tiny slice of an enormous whole. My heart pounds. My breath shortens, exploding from my mouth in roiling plumes of white. It's freezing in here. I don't remember ever feeling so cold.

With shaking fingers, I reach into my pocket and fish out the capsule. It slips from my grasp and spins like a lure through water toward the top of the pod. I catch it after a couple of tries, closing my fist tightly around it.

Damn, I'm cold. My teeth are chattering. I can't keep my thoughts still. What else? Is there anything else? What have I left undone? There isn't much-I am more than the sum of my own experience now. I've got ten thousand times my fair share.

Because here's the thing: Seeing yourself through another's eyes shifts your center of gravity. It doesn't change the way you look at yourself. It changes the way you look at the world. Not the you. The everything-but-you.

I don't hate you anymore, I tell the mothership. And I'm not afraid of you anymore. I don't hate anything. I'm not afraid of anything.

At the center, right in the middle of my view, a black hole grows, reminding me of a mouth slowly opening. I'm headed right for it.

I slip the capsule between my lips.

No, the answer is not hate.

The black hole expands. I'm falling into a lightless pit, a void, the universe before the universe was the universe.

And the answer is not fear.

Somewhere in the mothership's belly, thousands of bombs twenty times the size of the one in my mouth are rolling down chutes into launching bays. I hope they're still in there. I hope they haven't started to fall. I hope I'm in time.

The pod crosses the threshold into the mothership and jerks to a stop. The window's frosted over, but there's light outside; it glimmers in the ice. The hatch behind me hisses. I must wait until it opens. Then I must rise from this chair. Then I must turn and face what waits for me out there.

We're here, and then we're gone, he said to me, and it's not about the time we're here.

There's no unraveling us, no place where I end and he begins.

There's no unraveling any of it. I am entwined with everything, from mayflies to the farthest star. I have no boundaries, I am limitless, and I open to creation like a flower to the rain.

I'm not cold anymore. The arms of the seven billion enfold me.

I rise.

Now I lay me down to sleep . . .

I draw in deep my final breath.

When in the morning light I wake . . .

I bite down hard. The seal breaks.

Teach me the path of love to take.

I step into the out there, and breathe.

ZOMBIE.

I'VE REACHED THE GRAVEL PATH that borders the security fence when the sun breaks the horizon-no, not the sun, it can't be, unless the sun's decided to rise in the north and has swapped its gold for green. I whip to my right and see the stars winking out one by one, obliterated by a massive burst of light on the edge of the northern horizon, an explosion in the upper atmosphere that washes over the landscape in a flood of blinding green.

My first thought is for the kids. I don't know what the hell is happening and I haven't connected the projectile hurtling from the base to the enormous northern flare. It doesn't occur to me that for the first time in a very long time, something might have actually gone our way. Honestly, when I saw the light, I thought the bombardment had begun and I was witnessing the first salvo in the destruction of every city on Earth. The idea that the mothership could actually be gone didn't even cross my radar. How could it be gone? That ship's unassailable as the moon.

I hesitate, trying to decide whether to keep going or turn back. But the green light fades, the sky glows rosy again, and no terrified children burst from the woods seeking rescue. I decide to maintain my heading. I've got faith in Nugget. He'll know to stay put till I return.

Ten minutes inside the base and I find the first of many bodies. The place is a tomb. I walk through fields of the dead. They lie in piles, groups of six to ten, their bodies contorted into portraits of silent agony. I stop to examine every gruesome stack, looking for two familiar faces; I'm not going to rush, though a voice screams in my head with each passing minute to hurry, hurry. And in the back of my mind I'm remembering what happened at Camp Haven-how Vosch was willing to sacrifice the village in order to save it.

This might not be Ringer's doing-it may be the result of Vosch exercising the final option.

It takes me hours to reach the last level, the bottom of this death pit.

She barely lifts her head when I open the stairwell door. I may have shouted her name; I don't remember.

I also don't remember stepping over Vosch's body, but I must have: It was in my way. My boot hits the kill switch lying beside her. It skitters across the floor.

"Walker . . . ," she gasps, pointing over my shoulder down the long hallway. "I think he's-"

I shake my head. She's hurt and still imagines I'd worry about him for even one second? I touch her shoulder. Her dark hair brushes the back of my hand. Her eyes shine. Their brightness goes all the way down.

"You found me," she says.

I kneel beside her. I take her hand. "I found you."

"My back is broken," she says. "I can't walk."

I slide my arms beneath her. "I'll carry you."

BEN.

THE LATE-AFTERNOON SUN polishes the dusty windows of the superstore a lustrous gold. Inside, the light has faded to gray. We've got less than an hour to beat the dark back to the house. The day may belong to us, but the night belongs to the coyotes and the packs of wild dogs that roam the banks of the Colorado and wander the outskirts of Marble Falls. I'm well-armed, I've got no love for coyotes, but I hate shooting the dogs. The older ones were somebody's pet once; it feels like giving up all hope of redemption.

And it isn't just dogs and coyotes. A couple of weeks after we crossed the border into Texas, back in late summer, Marika spotted escapees from some zoo drinking a few miles upriver-a lioness and her two cubs. Ever since then, Sam has been itching for a safari. He wants to capture and tame an elephant so he can ride on it like Aladdin. Or catch a monkey to domesticate. He isn't picky.

"Hey, Sam," I call down the aisle. He's wandered off again in search of treasure. Lately it's been LEGOs. Before that it was Lincoln Logs. He's developed a love for building things. He's made a fort, a tree house, and started on an underground bunker in the backyard.

"What?" he shouts back from the toy section.

"It's getting late. We have to make a decision here."

"I told you I don't care! You decide!" Something crashes off a shelf and he curses loudly.

"Hey, what'd I tell you about that?" I call over to him. "Watch your language."

"Fuckety fuck fuck, shithole."

I sigh. "Come on, Sam, we gotta haul this thing back three friggin' miles, which I'd rather not do in the dark."

"I'm busy."

I turn back to the display. Well, the prelits are useless. That leaves either the six, eight, or ten foot. The tens are too tall for the ceiling. Either the six or eight, then. A six would be easier to transport, but it looks like crap. The Texas heat has done a number on it. Needles bent and soft, big bare spots in some places where they fell off. The eights don't look much better, but they're not quite as scrawny. But eight damn feet! Maybe their storeroom has new ones in boxes.

I'm still debating with myself when I hear an all-too-familiar, all-too-sickening sound: a bullet racking into the chamber of a pistol.

"Don't move!" Sam shouts. "Lemme see your hands! Hands!"

I draw my own weapon and race down the aisle as fast as my bum leg will allow, slipping on the carpet of rat droppings and hopping over fallen shelving and ripped-open boxes, until I reach the toy section and the kid who's got a downed man at gunpoint.

My age. Wearing fatigues. A 5th Wave eyepiece hangs around his scrawny neck. He's leaning against the back wall beneath the board games, one arm pressing against his gut, the other on top of his head. My heart slows a little. I didn't think it was a Silencer-Marika killed the one assigned to Marble Falls months ago-but you can never be sure.

"Other arm!" Sam shouts at him.

"I'm unarmed . . . ," the guy gasps in a deep Texas drawl.

Sam says to me, "Search him, Zombie."

"Where's your squad?" I ask. I have a vision of being ambushed.

"No squad. Just me."

"You're hurt," I say. I can see the blood, mostly dried but some fresh, on his shirtfront. "What happened?"

He shakes his head and coughs. A rattle in his chest. Pneumonia, maybe. "Sniper," he manages after catching his breath.

"Where? Here in Marble Falls or . . . ?"

The arm pressing against his gut moves. I feel Sam tense beside me and I reach out and put my hand over the barrel of his Beretta. "Wait," I murmur.

"I'm not telling you anything, you infested piece of shit."

"Okay. Then I'll tell you: We aren't infested. Nobody is." I'm wasting my breath. I might as well tell him that he's actually a geranium having a very weird dream. "Hang on a second."

I tug Sam to the opposite end of the aisle and whisper, "This is a problem."

He shakes his head vehemently. "No, it isn't. We have to kill him."

"Nobody's killing anybody, Sam. That's done."

"We can't leave him here, Zombie. What if he's lying about his squad? What if he's faking being hurt? We have to kill him before he kills us."

His face turned up to me, his eyes shining in the dying light, shining with hate and fear. Kill him before he kills us. Sometimes, not often, but sometimes, I wonder what Cassie died for. The tiger's loosed from its cage and there's no capturing it. How do we rebuild what's been lost? In an abandoned convenience store, a terrified girl mows down an innocent man because her trust has been shattered. There's no other way to be sure, no other option to be safe.

You're safe here. Perfectly safe. That phrase still haunts me. Haunts me because it's always been a lie. It was a lie before they came and it's still a lie. You're never perfectly safe. No human being on Earth ever is or ever was. To live is to risk your life, your heart, everything. Otherwise, you're just a walking corpse. You're a zombie.

"He's no different from us, Sam," I tell him. "None of this will end until somebody decides to put down the guns."

I don't reach for the weapon, though. It should be his decision.

"Zombie . . ."

"What did I tell you about that? My name is Ben."

Sam lowers the gun.

In the same moment, at the other end of the aisle, another silent battle is lost. The soldier lied; he was armed, and he used the time he had left to put the gun to his head and pull the trigger.