I conveyed this to Clearance, who tipped his head. “Not wise at all,” he murmured. “But if there’s the slightest hint of danger, I’ll grab you up so fast…”

His expression brooked no disagreement.

Glow and I walked out on solid, rocky ground. Our feet pushed up a fine cloud of spores. “We cannot contain all the memories of our ancestors,” the old female said. “We do not want them. We wish to be ourselves, with our own memories. And so they are kept here. When we need the past, which is rarely, we come here. We walk this way, and we walk back. When we return, we have what they need.”

“A biological Domain,” I said.

“I do not know that word,” the old female said, walking ahead. “I have only been here once, when I was young and we had a dispute regarding a matter of law and tradition. The ones who were in power then were shown to be wrong by what we brought back, the memories and traditions we carried. They stepped down and were replaced. No one defies this place or what it holds.”

Stripped of all technology, left to their own ingenuity, the ancient Forerunners had created a completely organic and living way to store their histories. “Do you know how far back this memory goes?” I asked, bewildered by the possibilities.

“To the beginning. Days ago, we see a light in the sky like a moving star, and it is you. I have a memory…”

She turned and held up her hands, then slowly lowered them, along with her head, and got down on her knees, not before me, but the far cliffs that rose thousands of meters into the dusty skies.

“The first of us scratched and drew and marked those cliffs with whatever they had available—rocks, sticks.”

The yellowish dust coated my garments and my skin. Some of it irritated my nose and lungs. I wondered what I would dream tonight, or remember in weeks to come.

The old female pushed painfully to her feet and walked toward the cliffs, then looked over her shoulder and urged me on.

The high rock walls were hung with orange, fibrous growths, like lichen or moss, moving slowly over the smoothly and naturally planed surfaces. Along their course, the mosses clung with rasping roots. Where patches had died and fallen away, they revealed etched symbols—many kilometers of them, arrayed in spirals and whorled radiances. While I now recognized the script, and the methods of reading the symbols seemed familiar, the symbols themselves were still hidden from me and could not be deciphered by my ancilla.

“These mosses are sisters to us. They travel back and forth from one end of this valley to the other,” the old female said. “When wind and dust and rain wipe away what they carve, they slide back and replace it, always with the same memories.”