The city was their home. Top floor of a narrow brownstone, no elevator, hallways as dark as caves. They lived near a train yard, where the tracks intersected like arteries. Twice a day, the passing trains shook their tiny apartment like a toy. It was not an extraordinary place, but extraordinary things would happen there.

A history of the city: there were no seasons. No flowers or sunshine or stars or clocks. They were neither north nor south. The tall buildings were rusted and empty, like abandoned machines. The trains never stopped. No one came or went. A limestone ash tree stood in the center of the city. It was tall as a skyscraper, a monument to nothing. If you climbed to the highest point of the tree and looked out, you would see that the city was surrounded by an ocean, the water as black and still as oil.

In bed, Nell’s eyes would freeze inside her head. Until they thawed, they would be wide and unblinking, like a doll’s. At the most pleasurable moment, Meno’s open mouth would glow with fire.

Nell was a cool woman. Her exhalations were white streaks. Ice crystals nested in her hair like barrettes. Meno was forever on the brink of being engulfed in flames—red-rimmed ears, sweat-slick skin. She dreamed of the dark, cold waters of a seacoast. He imagined standing deep inside a forest, surrounded by trees with canopies so dense, the sky would molt with green. The city, with its grayness and trains, was a compromise neither of them could remember making.

Fire and ice, their friends called them, because they were so different. How did you ever find each other? These friends were wan, both in spirit and in body. They were struggling to find the right way to live. Nell and Meno would smile and shrug, feigning coyness, but the truth was they could not remember how they met. It was as though they had just woken up one morning in this apartment, in this city, these lives unfurling like rugs before them.

In bed, Nell’s eyes would freeze inside her head. Until they thawed, they would be wide and unblinking, like a doll’s. At the most pleasurable moment, Meno’s open mouth would glow with fire.

What about children? their friends were always asking. Half fire and half ice! How lovely they would be! Once Nell let snow rain from her fingertips until a tiny snowman stood frozen on the floor. See? she said. Birth is not the only way to create. Meno rested a hand on the snowman’s shoulder and melted it down to a gray lump. You have the best party tricks, said the friends.

Where did these friends come from, anyway? Nell sometimes thought, but there was no answer to that either. They had just appeared, hovering around her and Meno like vapors.

It was the nature of cold to be steady and still. It was the nature of fire to catch, to spread. Their situation was not sustainable, and yet it was being sustained.

One morning, Nell woke to the smell of smoke. At the foot of their bed, a baby with fire-covered hands was burning holes in the sheets. The ice crystals in Nell’s hair melted; water dripped down her spine. She shook Meno awake. Around them trains rumbled.

Meno scooped up the baby and ran from the bedroom, his feet so warm they darkened the floorboards. Nell followed his footprints into the kitchen, where another infant was squirming across the floor. The child crawled toward her and grasped her ankles. One set of fingers numbed her skin; the other left a hand-shaped burn.

Their friends came by and placed bets on which one would grow up to rule the world.

Here was the problem with fire: you could never predict how it would spread. Meno had only wanted one, maybe two, but the children kept appearing. One emerged from the puddle of sweat at his feet. Another crawled out of his armpit. None of this seemed to cause him any pain.

Soon it was all they could do to keep these children from singeing the draperies or shattering the glass windowpanes with a single touch. When the trains passed, the babies shook their fists and wailed. Their friends came by and placed bets on which one would grow up to rule the world. What a beautiful family! they cooed. They never stayed for long.

One morning, to calm herself, Nell made another snowman and watched, uncomprehending, as the figure turned into a child. She began to sob and soon the tears that dropped to the floor became children too.

Nell and Meno read a parenting book. They were advised to leave the house once a day. They went for a walk through a barren city park, each of them pushing a large stroller. The sky was dark and growling. They tried to teach the children the words for rock and tree. To demonstrate, she and Meno patted the trunk of a leafless tree and another child stepped out of the bark.

We’ll never be able to find a babysitter, she cried to Meno on the way home. Not for a million dollars.

Time passed. Meno kept ice packs pressed against his forehead, trying his best not to sweat. Nell didn’t create anything from snow. They stopped reading. They didn’t go outside. No more children appeared. Maybe the flood was over. Maybe they would survive.

One night, they attempted the kinds of things they used to do in bed. The babies were sleeping in the wicker bassinets scattered across the apartment. One in the bathtub. Another nestled in an armchair. Another in the dark of the linen closet. The trains had finished for the night. Meno’s lips were feverish. Nell’s breath loomed above her like a cloud.

But something was not right. When Meno touched her, a pain flared in her belly. He pressed against her and she began to spark, like flint to steel. Right away she could tell that these were not the lights of passion, but of destruction. Lightning striking a tree. A power line meeting water. A line of fire racing toward a barn. She heard a crackling. The flesh underneath her belly button burned. Meno breathed chilly air onto her throat. His lips were hard and cold as stone.

If only he had realized that parents rarely outlive their children.

Fire and ice, that’s what they do to each other in the end, their friends would later say. But first the bodies of Nell and Meno would burn a hole in the apartment roof. First the children would rise from their bassinets and walk naked into the city streets, hearty and hale as giants. They would all look up and see a light blazing in the sky. They would feel their blood warm, their bones turn dense as ice. They would feel the beginnings of language sitting like a stone on their tongues. They would think that this, finally, was what it must mean to be alive.

Laura van den Berg’s debut collection of stories, What the World Will Look Like When All the Water Leaves Us (Dzanc Books, 2009), was a Barnes & Noble “Discover Great New Writers” selection and shortlisted for the Frank O’Connor International Award. Her second collection, The Isle of Youth, will be published by Farrar, Straus & Giroux in November 2013. She teaches in the creative writing program at George Washington University and lives in Baltimore.