My name is Little Mary, and I live in a city beneath New York.

The city has one hundred thousand people, and we are all small—about three inches tall. We live in the old subway tunnels, in spaces that the Giants forgot when they built their world above us. Our streets are made from flattened bottle caps and broken tiles. Our buildings are constructed from matchboxes and gum wrappers and anything else that the Giants dropped and didn't notice.

I work in the Light Maintenance Guild. My job is to keep the bioluminescent fungi growing in the ceiling lamps. The fungi are important. Without them, the city would be dark, and without light, the moss we eat would die, and without moss, we would starve. So I spend my days climbing ladders made from paperclips and trimming the fungi with scissors made from a shard of razor blade, making sure they glow bright enough to see by and not so bright that they burn out.

It is honest work. It is not exciting work. But it is mine, and I am good at it, and that is more than most people can say.

The city has other jobs, of course. There are farmers who tend the moss gardens. There are builders who repair the walls with a paste made from crushed shell and swamp clay. There are teachers who teach the children to read using books made from pages torn out of Giants' magazines—the words are huge, like boulders, and learning to read them is like learning to climb a mountain.

There are also stories. Stories about the Giants, who used to walk above us and didn't know we were here. Stories about the Great Falling, when the world above changed and the surface became hot and then cold and then something neither, forcing our ancestors to descend into the tunnels and learn to live in the dark. Stories about the Elder, the oldest person in the city, who remembers the time before the Great Falling and speaks of a world that was green and loud and full of things we can barely imagine.

I used to think the stories were just stories. Then the Observer came.

He appeared in Tunnel Four, which runs beneath what used to be Central Park. One day the tunnel was empty, and the next day there was a Giant standing in it, so large that his head nearly touched the ceiling and his boots were the size of our entire plaza.

He was wearing a dark coat and carrying a metal box that gleamed in the light from the fungi. He stood there for a long time, just standing, looking around with eyes that were the size of dinner plates and held an expression that I can only describe as sorrow.

Nobody moved. Nobody breathed. One hundred thousand people stood in the streets and plazas and windows of the city, staring up at a creature that was larger than anything we had ever seen.

The Elder was the first to speak. He climbed onto a podium made from a brick and raised his arms.

"Great Giant," he said, in a voice that carried through the tunnel like a bell. "What do you want?"

The Giant blinked. He looked down at the Elder, and for a moment I thought he might speak. But his mouth didn't move. Instead, he reached into his coat and pulled out a small object—a glass jar, no bigger than a thimble from our perspective, and placed it gently on the ground.

Then he turned and walked away. His footsteps shook the ground like distant thunder. He disappeared around the bend in the tunnel, and we were alone again.

Nobody spoke for a long time. Then the Elder climbed down from the podium and approached the jar. He picked it up—it was heavier than he was—and carried it to the Council.

Inside the jar were seeds. Real seeds, not the mutated things that grow in the radiation zones above. Real seeds, small and brown and impossibly alive.

"The Giants have been watching us," the Elder said, holding the jar up so everyone could see. "And they have decided to give us this."

"What are they?" asked a young farmer named Eli.

"Answers," said the Elder. "Or maybe questions. I'm not sure which."

I was not at the Council. I was in my apartment, mending a tear in my work tunic, when the news came. Seeds. A Giant. A jar placed gently on the ground like it was something precious.

I put down my needle and went outside. The city was buzzing—literally, because the fungi seemed to glow brighter, and figuratively, because everyone was talking at once. Some people were excited. Some were afraid. Some were angry.

"Why give us seeds?" Eli said. "What do they want?"

"Maybe nothing," said an old woman named Rosa. "Maybe they just wanted to give."

"Giants don't give," said a man named Thomas. "They take. That's what Giants do."

I didn't say anything. I had seen the Giant's face, or at least the part of it that I could see from where I stood. His eyes had been sad. Not cruel. Not indifferent. Sad. And I knew something about sadness—I had my own, in the small and unremarkable ways that small people have sadness: the loneliness of a job that nobody notices, the ache of loving someone who loves someone else, the quiet desperation of knowing that you will never be anything more than you are.

That night, I climbed the tallest ladder in the city. It was made from thirty-seven paperclips linked together, and it reached the ceiling of the tunnel, where the bioluminescent fungi grew thickest. I sat among them, legs dangling over the edge, and I looked up at the dark passage where the Giant had disappeared.

I thought about the seeds. I thought about what they might grow if planted—tall things, probably. Things that would stretch up toward the ceiling and maybe, if they grew tall enough, touch the world above.

I thought about the Giant's sad eyes. I thought about how he had placed the jar gently on the ground, like it was something precious. And I thought about something the Elder had told us once, in a speech about the meaning of existence:

"When a Giant looks at you, you are either invisible or extraordinary. There is no in between. The question is not whether he sees you. The question is what he sees when he looks."

I didn't know what the Giant had seen. I didn't know if he had seen us at all, or if he had simply passed through the tunnel and left the seeds as a gesture without meaning, the way a man might drop a coin in a fountain and not think about it again.

But I knew this: he had come. He had seen us, or failed to see us, and either way, he had left something behind. And that changed everything, because now we knew that we were not alone. Whether the Giant above us knew it or not, we were connected to him—by the seeds he had left, by the sadness in his eyes, by the simple fact that he had been there and we had been here and for one brief moment, our worlds had touched.

The next morning, I went to work as usual. I climbed my paperclip ladder and trimmed the fungi and made sure they glowed bright enough to see by. But I did it differently. I did it with the knowledge that somewhere above me, a Giant was walking through a world that was no longer entirely his, carrying sadness like a heavy coat, and that somewhere below me, one hundred thousand small people were planting seeds in warm soil, waiting for something green to break through the dark.

I trimmed a fungus that was growing too thick and watched its light dim slightly. It was a small thing. Insignificant, probably. But it was mine to do, and I did it well, and that had to be enough.

Above me, the tunnel was empty. Below me, the city hummed with the sound of one hundred thousand lives, each one small and each one essential.

And somewhere in between, the seeds waited.