When the heatwave apocalypse hits the Earth, the ozone layer has completely dissipated, forcing mankind to move into the underground city.

My husband, Rhett Calloway, and I get to stay on Level Two, seeing as we've funded the construction of the underground city.

On day in the third year of the heatwave apocalypse, Rhett brings back a sickly young woman from the slums located on Level Three out of the blue.

"Nora, the living conditions on Level Three are very difficult. Anna is in poor health. I can't just sit by and watch her suffer."

After that, Rhett carries Anna Archer into our home.

I keep my gaze lowered as I remind him, "Don't forget that there's a strict population count on Level Two. The available slots in every family are fixed."

"I know that. That's why you need to head down to the slums on Level Three to replace Anna for the time being. Once she recovers from her illness, I'll bring you home."

The moment I hear Rhett's response, I remain rooted to the spot for a long time.

After walking out the front door, I do my best to suppress the quiver in my tone as I call a number that belongs to Level One.

"I've already thought it through. I've decided to join the project to end the apocalypse on Level One."

The voice on the other end crackled with excitement. "Nora, this is incredible. Level One needs someone like you!"

The underground city was divided into three levels.

Level One was a classified research and technology sector, the beating heart of the entire city, sealed off from the general population without exception.

Level Two was home to those who had earned their place through contributions to the city's founding.

Level Three, as the years wore on, had become something else entirely, the darkest corner of a world that had already lost most of its light.

I had just hung up when Rhett Calloway stepped out of his room. He pressed two fingers to his temple, voice heavy with fatigue. "Anna's condition is serious. She needs medical supplies."

"And what exactly are you planning to do about that?" I asked. I kept my back to him, afraid he might see my face.

Rhett's voice was low and hoarse. "Treat her, obviously. No matter what it costs. I've already sent for a doctor."

Three years into the apocalypse, medical care had become one of the most guarded luxuries left. Every household was allotted a single doctor's visit per year, nothing more.

A month ago, when my fever hit 104 and my vision blurred at the edges, I had bitten down and suffered through it alone, unwilling to waste the one chance we had.

Rhett had just spent that chance on a woman he met last week. He didn't notice what that did to me. His voice stayed flat and even. "Nora, I've made arrangements. Someone will come in three days to take you down to the Level Three slums. You'll go in Anna's place."

I shut my eyes for a moment. When I turned, I dragged my fingertips quickly across the corner of my eye before he could see anything.

"Rhett, did you stop, even once, to think about what you're asking of me?"

He didn't flinch and said, "You know how I am. I can't watch someone die and do nothing. I never could."

I almost laughed. There were thousands of people suffering out there, yet somehow it still came down to her.

He must have read something in my expression, because he kept going. "I was passing through Level Three when I saw her. She was sitting with the slum children, singing to them. Just singing, like the world hadn't ended. Tell me how I'm supposed to walk away from something like that."

I took two steps back and forced my voice to stay steady. "So I'm the one who pays for it? Shipped off to the Level Three slums to live her life for her?"

Level Three was lawless and volatile, the kind of place where survival was never a given. People disappeared there without explanation.

Rhett's expression tightened. "Don't be dramatic, Nora. It's not a sacrifice. It's a temporary arrangement."

Before I could respond, a knock came at the front door. He was already moving toward it.

I found the back of the couch with my hand and held on. Through the gap in the doorway, I could see Anna Archer lying in bed, lips pale, breathing shallow. A cough tore through the quiet.

Rhett rushed the doctor to her side without a backward glance. I stayed exactly where he'd left me. There was no wind underground, yet I had never felt colder.

The doctor didn't leave until well past midnight. Rhett found a moment between everything else to say what amounted to a dismissal.

"You've seen her yourself. She needs complete rest. Three days, Nora, and then you go to Level Three. If you don't, our household won't clear the Level Two headcount inspection."

I looked up at him. I was so tired. There was a dull, spreading ache somewhere behind my ribs that I didn't have a name for yet.

Then my phone buzzed.

"Ms. Nora Vale, in three days, a designated representative from the organization will arrive to escort you to Level One."

I silenced my phone screen without a word and managed a thin smile in Rhett's direction.

"Fine. I'll go."

Where I actually went was my own business.

He let out a slow breath, then leaned in and pressed a brief kiss to my forehead. "I knew you'd understand. Don't worry, I'll bring you back soon."

I wiped the spot with the back of my hand once he looked away.

That night, Rhett stayed by Anna's side without once changing out of his clothes. I sat on the couch all night, chasing sleep that never came, my mind dragging me back through things I'd rather have forgotten.

Rhett had grown up on a scholarship funded by Dad. His grades were exceptional, good enough that Dad had arranged for him to study abroad alongside me.

Back then, he once crossed half the foreign city just to bring me a slice of cake. When I couldn't stomach the food there, he showed up outside the campus gates every evening with a covered lunchbox, waiting.

Now, he couldn't stand the thought of someone like Anna being swallowed up by a place like this.

But Rhett seemed to have forgotten. Seven years ago, he had sworn, at Dad's bedside, that he would always protect me. He promised that the Vale name would never fall as long as he was standing.

The apocalypse hadn't come yet that year. His vows had sounded like they were meant to last forever. Now those same words just felt like a cruel joke.

He used to be such a good man. I couldn't make sense of what had changed.

But I understood one thing clearly enough. Whatever came next, I didn't need him to be part of it.

By the time the ceiling lights had cycled back to their morning setting, Rhett was already in the kitchen, which was rare. He was cooking a pot of chicken noodle soup for Anna.

I walked past without looking at him, went into the bedroom, and pulled my suitcase out from under the bed.

Anna had made it through the night. The small noises stirred her awake, and our eyes met across the room.

Then something seemed to snap in her. She scrambled off the bed and threw herself at my feet, knocking her forehead against the floor over and over.

"Please don't hit me. I'll behave, I promise. I'm good, I'm good, please don't hit me."

I stared at her, caught completely off guard. Footsteps came crashing down the hall.

"Nora! What did you do?"

Rhett burst through the door and scooped Anna into his arms. The look he turned on me was red-eyed and raw.

He never lost his composure. Three years ago, when the world ended, and we lost our daughter, Ophelia Calloway, on the road out of the city, he hadn't even flinched. And yet here he was, undone by a woman he had barely known.

Anna trembled against his chest, tears sliding down her face. "Please, please don't send me back to Level Three. I can sing for you. I'll sing anything you want."

Rhett pulled her closer and spoke to her in a voice I barely recognized, soft and certain. "You're safe. I'm right here."

Then he looked at me, and his tone changed completely. "Anna went through things down there that no one should have to survive. Stop trying to frighten her."

I exhaled slowly. A deep, bone-tired kind of exhaustion settled over me.

"Rhett, I used to think you were the blind one. Turns out it was me all along."

I was blind enough to give him my entire youth.

Something flickered behind his eyes. He opened his mouth, but I was already walking out.

It was strange. When something broke a person badly enough, there was nothing left to fight with.

I went to the study and opened the pocket watch on the shelf. Inside was a photograph of the three of us, back when there had been three of us. The faces smiling up at me stung in a way I wasn't prepared for.

The day we fled underground, Ophelia lost her footing at the edge of a fissure in the earth. There was nothing left to bury. I cried until I had nothing left, and Rhett arrived long after.

The memory pressed down on my chest like a physical weight.

The door opened. Rhett leaned against the frame, watching me turn the pocket watch over in my hands. His expression was hard to read.

"It was an accident," he said. "If she were still here, she wouldn't want to see you like this."

He then set a bowl down on the desk. "Eat something. Your stomach's always been sensitive."

I closed the watch. "You can take Anna's leftovers back."

His jaw tightened. "Nora, I'm only asking you to spend a few months in the slums. That's all. Are you really going to make this into something it isn't? Anna managed three years down there, and she's half your size. What's your excuse?"

I looked at him. "Then why don't you go?"

He didn't catch it at first. When it landed, the color drained from his face.

"Because someone has to keep this household together. If I leave, what's left? And let me be clear. If I hear you've given Anna a hard time, don't expect me to bring you back."

The door slammed behind him. I stood by the bookshelf and laughed quietly to myself. Three years in the apocalypse, and he still hadn't figured out where he actually stood.

"Rhett, did you forget? Without me, you never would have had a place on Level Two to begin with."

Before the apocalypse, I had been a core researcher at the institute. I gave up my spot on Level One for Rhett, choosing to follow him to Level Two instead.

Never mind that the Vale family had funded the underground city's construction. Without me, Rhett wouldn't have had the standing to set foot even in Level Three.

But in the end, talent was the only currency that still mattered down here.

On the second night before I was due to leave, I stayed up past midnight sorting through my files. I was nearly ready to give in to sleep when sounds drifted through the wall and killed it entirely.

My fingers went still. I set down what I was holding and made myself walk out of the study.

What was coming from the bedroom left little to the imagination. I didn't open the door. I didn't need to.

Then Rhett's voice, low and rough, came through the wall clearly enough. "Anna, will you give me a child?"

My hand froze on the doorframe.

After our daughter died, the underground city had issued us a single reproductive permit, part of the program to sustain the population.

Rhett had turned it down himself. He said our daughter, Ophelia, was the only child he ever wanted. He said he would never have another.

Apparently, that wasn't quite the truth. He hadn't wanted another child with me. He had been saving that permit for Anna.

He was even taking away my right to become a mother again.

I walked back to the study in a daze and sat down. Whatever had remained of my feelings for Rhett dissolved quietly and completely, and I didn't try to hold onto any of it.

When morning came, Anna appeared in the doorway with a sheepish expression. "Nora, I hope we didn't keep you up last night."

"Get out."

Her eyes went red immediately. "I didn't mean to make noise, I swear. I could sing something for you if you want. I'm really good at…"

I didn't say another word. I just walked her out by the shoulders. She stumbled a little as I pushed her through the door, and a photograph slipped out of her pocket and fell to the floor.

I picked it up. It was a signed photo, and something about the face tugged at my memory. Before the apocalypse, Anna had been a singer.

She brightened immediately. "Do you want me to sign one for you too? Rhett used to come to all my shows back then."

I frowned and turned the photo over. On the back was a picture of Anna and Rhett together. A date was printed in the corner.

March 21, 2060.

The world tilted. That was the day the apocalypse hit, the day we fled, and the day Ophelia fell into the fissure and never came back up.

So they had known each other all along. Rhett hadn't been held up at work that day. He had been with Anna, and Ophelia had spent her last moments waiting for him to come.

In the end, the fissure closed over her. There was a brief red mist, and then silence.

I pressed a hand to my chest. The pain was bad enough that breathing took effort.

The door swung open. Rhett stepped in without looking at me. "Anna, time for your medication."

I raised my head and stared at him. He glanced at me briefly, unimpressed. "What are you looking at? What is it this time?"

I stood slowly. When I spoke, my voice came out very quiet. "What were you doing the day our daughter died?"

He set down the glass of water. "I…"

I crossed the room and slapped him. Then I held the photograph up in front of his face. "You told me you were working. So tell me what this is."

His eyes locked onto the photo and didn't move. "Nora, just let me explain. I only—"

Anna burst into tears from across the room. "Please, please don't fight. I can't stand it. I'm scared. I'm so scared…"

She cried until she hyperventilated and went limp. Rhett stopped mid-sentence and caught her before she hit the floor.

I was shaking. "Rhett, if you walk out that door, you will regret it."

He glanced back at me, his voice measured and flat. "You're too upset to talk right now. Calm down first, and then we'll sort this out."

He walked out anyway.

Anna was cradled against his arm, her head tipped back. As he carried her through the door, she turned and looked straight at me.

The helpless, frightened expression was gone. Her eyes were completely clear.

She mouthed the words to me. "Sorry, Nora. I have to stay on Level Two."

After they were gone, the room was so quiet I could hear my own tears hitting the floor. So Rhett hadn't changed overnight after all. It had been happening slowly, quietly, long before I was willing to admit it.

Something almost like relief moved through me, and I laughed at myself for it. It had taken my heart breaking completely before I could finally see straight. When I was done, I wiped my face and picked up my phone.

"Yes, is this the Level Two security office? I'd like to report someone. There's an unregistered Level Three resident being harbored at this address."