Because a human passed through it completely. Because if the barrier had not come down, you would have died.
To Nafai it seemed like the voice of the Oversoul inside his head.
(Yes, I'm here, you know me.)
"I destroyed the barrier?"
(No, I did. As soon as you passed all the way through, the perimeter systems informed me that a human being had penetrated. All at once I became aware of parts of myself that had been hidden from me for forty million years. I could see all the barriers, knew at once all their history and understood their purpose and how to control them. If you had been some exceptionally determined intruder who didn't belong here, I would have told the perimeter systems to let you die; they would have immediately been hidden from me again. That has happened twice before, in all these years. But you were the very one I meant to bring here, and so the purpose of the barrier was finished. I ordered its collapse, bringing oxygen to you and, therefore, to the rest of this place.)
"I appreciate that decision," said Nafai.
(It means that decay has reentered this place. Not that it has been wholly excluded. The barrier excluded most harmful radiation, but not all. There has been damage. Nothing here was meant to last this long. But now that I can find myself instead of running into the perimeter system blocks, maybe I can figure out why I was looping.
(Or Issib and Zdorab can figure it out - they're at the Index even now, and the moment you passed through the perimeter, the blocks went down for them, too. I've shown them everything you did, and they're now searching through the new areas of memory opened to all of us.)
"Then I made it," said Nafai. "I did it. I'm done."
(Don't be a fool. You got through the barrier. The work is only just beginning. Come to me, Nafai.)
"To you?"
(To where I am. I have found myself at last, though I had never been able to think of searching for myself until now. Come to me - beyond those hills.)
Nafai searched for his clothes and found them scattered - winds that could blow his body around had easily snatched his clothing out from under the stones. What he needed most were shoes, of course, to make the trek across the stony ground. But he wanted the other clothes, too - eventually he'd have to come home.
(I have clothing waiting for you there. Come to me.)
"Yes, well, I'm coming," said Nafai. "But let me get my shoes on whether you think I need them or not." He also pulled on his breeches, and pulled his tunic over his head as he walked. And the bow - he searched a moment for his bow, and didn't give up until he found a piece of it and realized that it had broken in the wind. He was lucky that none of his bones had done likewise.
At last he headed out in the direction that the Oversoul showed him inside his mind. It took perhaps a half hour of walking - and he wasn't quick, either, his body was so bruised and sore. Finally, though, he crested the last hill and looked down into a perfect bowl-shaped depression in the earth, perhaps two kilometers across. In the center of it, six immense towers rose up out of the ground.
The recognition in his mind was instantaneous: the starships.
He knew the information came from the Oversoul, along with many facts about them. What he was seeing was really protective shells over the tops of the ships, and even then, only about a quarter of each ship rose above the ground. The rest was underground, protected and thoroughly linked into the systems of Vusadka. He knew without having to think about it that the rest of Vusadka was also underground, a vast city of electronics, almost all of it devoted to maintaining the Oversoul itself. All that was visible of the Oversoul were the bowl-shaped devices that pointed at the sky, communicating with the satellites that were its eyes and ears, its hands and fingers in the world.
(For all these years, I have forgotten how to see myself, have forgotten where I was and what I looked like. I remember only enough to set certain tasks in motion, and to bring you near here to Dostatok. When the tasks failed, when I began looping, I was helpless to help myself because I couldn't