WHEN I LEAVE THE HOSPITAL, I drive to the barracks where my brother, his wife, and children are housed. I stand outside and wait, knowing that I’m not going to go in, that they don’t want to see me. But I want to see them. If only to know that they’re okay.

Everyone in the evacuation camps has to work. That’s the deal. The United States and its allies evacuate you, give you a new home, and food, clothing, and shelter from the Long Winter—and you have to work. In some ways, this new world has become a classless society. Everyone works together to survive. At least, everyone in the same alliance.

The door to the barracks swings open, and people pour out into the morning sun wearing thick clothes, heads down, trudging to their jobs. In the procession, I pick out my brother, talking to another tall man beside him, both smiling. That’s Alex for you: always one to adapt. Never one to begrudge his fate. He’ll do well here. I’m glad. And I’m glad I saw him.

But I can’t linger here. I have a trip to make. A very important one.

WHEN I MADE my request to Fowler, he questioned me at length. The kind of resources I asked for are hard to come by: a plane capable of crossing the Atlantic and landing anywhere and a team capable of excavating deep beneath the snow.

But he said yes. I know he had to make some calls and trade some favors, which are the only real currency left in the world.

The Air Force cargo plane is a noisy, vibrating behemoth that reminds me of a whale flying through the air. I try to sleep during the flight, but I can’t. I keep thinking about Emma, wondering how she’s doing, whether her five laps around the unit yesterday will be six or seven today or whether she’ll regress as she did two days ago. Doing what she’s doing—starting over, learning to walk again and being so weak and frail—would be hard for anyone. It’s especially hard for her, because she’s so strong. And so proud. But I’m proud of her. For enduring it with so much courage and poise and determination. I wonder if I could.

The Air Force colonel commanding the mission walks into the cargo hold and points at the headset. I pull it on and listen.

“We’re on approach, Dr. Sinclair.”

I look out the window at the frozen ground below, the white expanse with no end. There was no satellite footage to go on, but I was optimistic that we might at least see the top of the house. No such luck. It’s buried.

ON THE GROUND, we use sonar to locate the house, and the Marines begin digging. The white sheet cracks like an egg as they tunnel into it, their breath coming out in white wisps of heat.

This location, just outside San Francisco, looks like Siberia now: ice and dim sunlight as far as the eye can see. A gust of wind catches me, cutting right through my parka, right down to my bones. I shiver and try to bear it.

The hole is growing bigger. It’s not a shaft straight down, but rather a tunnel leading to the house’s front door. The ice hasn’t collapsed the residence. That’s good news. It gives me hope.

When the tunnel reaches the porch, the Marines call up to us. I descend while they chisel the remaining ice away from the door and kick it open.

The inside of the house is an icy tomb. The Marines and I are wearing helmet lights that cut white beams through the darkness. Glimmering white crystals cover the furniture and chandelier, as if the home has been flash-frozen. It would be beautiful if the cold weren’t so deadly.

“Stay here,” I call out to the Marines.

I make my way to the kitchen and open a creaking door that leads down to the cellar. I shine my helmet light over the staircase, looking for any booby traps. If he were going to attack, now would be the time.

“Oscar?” I call into the darkness. No reply.

Is he gone? Did the Long Winter claim him?

I take another step. The narrow wooden staircase groans under my weight.

I continue down the stairs to the concrete floor. Even wearing the parka, I’m freezing. I won’t last long down here.

“Oscar? Can you hear me?” I wait.

“It’s okay. It’s James. If you can hear me, come out. We have to leave.”

I hear rustling in the corner. I turn, shine my light there, and breathe a sigh of relief when I see him. He’s okay. Unharmed. His skin is silky smooth, his hair short and brown, worn in the same fashion as mine, though he looks twenty years younger than I do, like a young man just beginning college.

“Sir,” he says softly. “I didn’t know what to do. You told me to stay here until you came for me.”

“You did the right thing.”

“I saw on the news that you were going into space.” “I did.”

“And you returned. Safely. I was worried.”

“There’s no reason to worry, Oscar. Everything’s going to be all right now.”

BACK IN TUNISIA, in Camp Seven, Fowler assigns me to my own habitat. It’s a solar-powered, two-bedroom white dome with a small kitchen, living space, and even an office nook. Space is at a premium here in the camp, and the residence is a luxury. I declined it at first, but Fowler insisted, saying that Emma would need live-in care even after she got out of the hospital. That comment got me thinking about where she would go after the hospital.

I sort of assumed she would want to stay with her sister. I can’t help but feel a little hopeful that she will in fact come back here.

An hour after I return to my habitat, Fowler knocks on the door. He lives two habitats down, and we’ve been meeting here and working together at night (we have offices next to each other at the new NASA headquarters, but he and I always bring work home). At the sight of Oscar, he stares, then gives me a curious look. I wonder if he’s figured it out.

“I’ll make arrangements to find you a three-bedroom habitat.” “That won’t be necessary.”

He squints at me and finally nods. “All the same, I’ll get you the larger habitat.”

I think he knows.

THE NEXT MORNING, just before I head out for work, there’s a knock at the door. I open it to find Pedro Alvarez standing there, wearing a thick coat and cap, shivering in the wind.

“Pedro.”

“Hi, Doc.”

“Come in. Please.”

He shakes the snow off of his coat and glances around the habitat. “Hope I’m not intruding.”

“Not at all. I was about to head to work, but I have a few minutes. It’s great to see you.”

“Likewise, Doc. There was a rumor going around about some brilliant scientist living in the camp. Guy who’s going to save us all. So, you know, I figured that was you, and I took a chance on searching the AtlanticNet. Found you in the directory.”

“I’m glad you did. What happened after you left Edgefield?”

Pedro shrugs. “They gave me a spot here in Camp Seven. Probably figured that would keep me from suing or giving a TV interview or something. Been here building habitats and working in the warehouses ever since.” He looks me in the eye and smiles. “I just stopped by to say thanks

—for what you did for me at Edgefield. You saved my life. Probably saved my whole family, Doc.”

“You would’ve done the same for me, Pedro.”

When Pedro’s gone, I can’t help feeling a little bit of pride. Since the encounter with Beta, I’ve struggled to stay positive. We’re facing impossible odds. A massive enemy, ruthless, relentless. It’s a lot like that riot in Edgefield. But Pedro and I got out of there. I helped save him. And seeing him fans the flames of hope inside me. Even long odds and massive enemies can be beaten.

FOWLER and I have come to several conclusions in the past few days. First, that we will share what we know with the Caspian Treaty nations and the Pac Alliance. The three superpowers are in agreement that a joint effort must be made to oppose the artifacts. Our conundrum is very simple: what to do. We know we’re at war. But with what? And how do we fight it?

Fowler and I have reviewed the data, trying to get our heads around what we know. We’re preparing a proposal, and soon we’ll visit the other superpowers and ask for help.

But first there’s something I have to know. I’ve asked Fowler before, but he wouldn’t tell me.

“I want to see the timeline. With the climate data.”

“That won’t tell us anything we don’t know,” he says quietly.

“It will. I need to know if I caused this—if my actions up there accelerated the Long Winter. It won’t affect me. I promise.”

He exhales heavily and types on his laptop.

I scan the data. I was right. The day we attacked the artifact, the climate on Earth changed dramatically—temperatures around the world plummeted. We did this. I did this. I caused the Long Winter to get worse. My actions out there did this. I’m responsible for the death of millions. Maybe billions.

I have to fix this. I might be the only one who can. And I’ll never be the same if I can’t.