And then my flashlight beam landed on a little face right below me, eyes wide and jaw hanging open, mouth clotted with teeth. My shoulder struck the wall with rattling impact and by the time I looked again the Child wasn’t there anymore.

Not visible, but still present. Crouched against the wall I could see them all again, the little darting shadow-children, moving out of the corners of my eyes, hiding from my flashlight beam. I panted in the thin air.

“Sean,” Tamara hissed, and I turned to find that she’d stopped, too. We’d reached the other side of the wheel.

“Follow me,” she said. She was already half inside the wall, just her head sticking out, the rest of her sticking what would become ‘down’ once we had gravity again.

There was hardly room for her in that chute. This one seemed even narrower than the first. It was the only way out and I knew it, but my heart started pounding even harder, fighting low oxygen and terror. “I don’t—”

“Yes, you can,” Tamara said. “Just follow me.”

Brigid had night terrors when she was a little girl. The first time I’d heard her shrieking, it had terrified me. The successive times, it had only annoyed me, because we’d shared a room at that age and each time she would wake me from a sound and peaceful sleep. I was a horrible child, to become indifferent to his little sister’s fear.

Eventually, after a week of this, and our parents signing her up for sessions with a therapist and changing her nighttime routine to try to shake the haunting, I’d asked Brigid why she screamed. What was it that frightened her?

There were shadows in the room, Brigid had told me; shadows that wanted to do her harm. Little shadow people, only as tall as she was, half the height our parents were. They gathered in doorways and crouched beside the dresser, and in the dead of the night they came out and gathered around her bedside like viewers at a funeral while she lay paralyzed.

I’d promised her that I would keep watch, that I wouldn’t let the nightmares reach her. She’d been young enough that it had comforted her, but it hadn’t been enough. So I’d distracted her every night before she went to bed, teasing and soothing, offering her stories and knowledge like Indigo had bargained with me, guarding her in two ways at once. Her night terrors had ceased.

As for me, I laid awake long nights after that, watching the shadows beside the dresser until I would swear I saw them tremor in the dark, reaching for my sister.

The Children moved around us, like little shadows, closer and closer. But Tamara spoke so calmly I found my own heartbeat slowing down.

“Indigo will have to wait to show you his name,” she said. “It’ll be safe down below. You can climb down this one, because you just climbed up the other one. I’ll be right ahead of you, clearing the space. Put your feet down after me and just take one step at a time. Don’t think of anything except the step right below.”