He heard another of those intense hissing sounds and realized it was right out in front of him, above the hospital courtyard where they’d dumped the chopper yesterday. Enough light was radiating outward from the windows of the building to make the source clearly visible: another of those silvery disks. When he caught sight of it, the thing was still falling. For it had simply dropped out of the sky. Plumes of white fog were screaming out of nozzles spaced around its perimeter—just like rocket exhaust, but cold, with no fire.