Forerunner vessel construction

“They’ve come to ask my help—or arrest me again. I think the former, and I think I know why—but Imust not help them. I’ve stayed here too long already. It’s time to leave. And all of you will come with me.”
“Where? How?”
My answer arrived even as I spoke. The platform was still rising. The circling pillars sprouted bulkheads, beams, and stanchions—all the necessary parts. The skeleton of a slipspace voyager was growing around us, almost too rapidly to track—until the pillars were walled in, the sky and the swirling ships vanished, and we were completely enclosed.
(Halo Cryptum; Ch.8)