“He must have loved us, Rowan, to give us all this,” Lachlan says. I won’t look at him. “He must have loved humans so much, to save us from ourselves.”

“I have work to do,” Flint said abruptly. “Lachlan, show her around.”

I try to protest, but Flint turns on his heel and is gone.

Lachlan reaches for my hand, but I shake him off before he can so much as touch me. Every time I look at him, I feel like the wet bag is over my head again, and I’m choking. He steps back and nods, gesturing for me to precede him, giving me space. I want to stay up here gazing at the tree, but then he says, “I know you want to touch it.”

I can’t resist that offer. I storm ahead of him, but it’s all I can do not to smile.

The walls are high, ringed with galleries at multiple levels. I can see many cave-like rooms all around. The interrogation chamber I just left is four stories up along the curving walls of the cavernous hall. I fly down stairs cut into the stone, getting curious glances from a few people. I’ll look at them later. Just a few days ago, other humans were exciting. But a tree! For the moment, nothing else exists.

I sprint across the smooth stone floor until suddenly my feet hit dirt. I skid to a stop and look down at my boots. Lachlan is behind me. “Take them off,” he urges, and I do, laughing as my bare toes grip the real, natural packed Earth. I touch it with my hands; I kneel. Ecstatically, I kiss it. I must look like an idiot, dirt on my lips, but I don’t care. I never thought I’d experience this in my lifetime. Everyone in Eden must endure artificiality for generations so that one day our descendants might know the glory of nature.

I meet Lachlan’s eyes, still smiling . . . and remember my night of torture. My smile dies, and I stand, turning away from him.

The tree looms before me, a true behemoth, dwarfing me as I creep closer. I pick up a dead leaf from the litter at my feet and rub it gently between my fingers, releasing a burst of that sharp, stimulating smell that permeates the air and makes me feel so alert and alive.

And then I’m touching the tree, tentatively at first, like a newfound love, then pressing my cheek against the rough, fragrant bark, embracing it. My tears wet the bark, soak into it, and are gone.

With my arms wrapped around the huge tree, my chin on the trunk, I look up into the canopy with all its myriad shades of light and dark green. As I look, a leaf detaches from its twig and drifts slowly down, tacking left and right in elegant swoops. I catch it in my hand. Can I keep it? One leaf is more precious than a jewel. I don’t care if I hang for it—I slip the leaf beneath my shirt, nestling it close to my heart. It is a gift from the tree to me.

“Stop! Look out!” a voice calls from behind me, and I whip around on high alert, ready for Greenshirts, for anything.

Anything, except being under attack from a horde of tiny people in patchwork clothes.

I haven’t seen children since I was one, and then only Ash. It feels strange to see this pack of screaming, laughing, tiny humans, and I brace myself as they surge toward me, having no idea what they will do, no real comprehension of childish behavior.

But they’re not running for me. As one they tackle Lachlan, clinging to his legs, squealing with glee and pretend aggression. And that big, hard man, the one who allowed me to be tortured, is suddenly on the ground beneath a pile of children, laughing, tickling them, letting them put him in headlocks, giving them rides on his back . . .

Which is the real Lachlan? The one who said that torturing me was perfectly fine? Or the one who is currently letting a four-year-old girl in pigtails pull his hair?

He flashes me a quick, almost apologetic smile before a little boy does a belly flop on his head and brings him down. “Lach!” they squeal. “You’re back! We missed you, Lach! What did you bring us? Did you fight anyone? Lach, tell us a story of the Above!”

“That’s quite enough of that, kidlets,” says a plump but solid maternal-looking woman as she bustles up behind the children. “Let Lachlan breathe.”

The tiny girl in pigtails looks up at the woman with huge, sincere eyes and says emphatically, “But Lach is our favorite.”

The woman nods. “I’ve heard that before, perhaps a bit too often.” She looks archly at Lachlan as he rises and brushes the dirt from his clothes.

And I realize, as the children gaze lovingly at Lachlan, that this is what he did it for. These little second children are the reason he thought it was justifiable to torture a girl who had just lost her mother, who had been hunted through the streets. They need to be protected, at any cost. Now that I understand, I wonder if I would do the same thing myself. I don’t know . . . but I understand why Lachlan did it, and I find that I can’t be mad at him anymore.

The woman holds out her hand to me. “I’m Iris, housemother of the Underground. Welcome.” I introduce myself, and she tells me to come to her if I need any clothes or personal items. “A ruffian like our Lachlan here wouldn’t think of creature comforts like lotion and nail files and such. We might be a bit primitive down here, but I like to think we manage to hold on to the best parts of civilization.”

She gives my shoulder a friendly squeeze and herds the children away. The children all say hello as they pass, making me feel welcome. All except the little girl in pigtails. She shakes my hand very formally, and then says, “You can like Lach a little, but not too much. He says I’m his favorite girl. Don’t you forget!” She shakes a warning finger at me and scampers off. I manage to keep a straight face until she’s gone.

“I’ll take you to your room,” Lachlan says. “I know you need to shower and change. Do you have clothes in there?” He nods to my backpack.

I don’t even know. I haven’t had a moment to open it.

“I’ll see what I can scrounge up in your size.”

“Thanks . . . Lach,” I say, and he grins sidelong at me as he leads me to my room.

ONCE I’M ALONE, the bed looks so inviting I want to flop down on it, curl beneath the crisp new-leaf green sheets, and sleep for years. But I’m so filthy I can’t bear to dirty the sheets, so I go into the little shower alcove and let the cold water wash over me until I’m approximately, if not completely, clean.

Being in this room—in the Underground itself—is like being in the heart of the Earth. The rooms are carved directly into the stone, and every surface is smooth, connected, without the edges and corners and seams of the rest of Eden. I know the rooms are man-made, not natural caves, but because the material is all-natural it feels almost like the Earth made this place for them.