As Knox sprinted across the frozen tundra, he summoned a thick cover of shadows. In seconds, total blackness shrouded him, hiding him—and Vale—from the view of others. “Can’t see,” she said, her teeth chattering. “So dark.” “You don’t need to see.” The urge to return to the prison and pick off survivors bombarded him, but his desire to save the little Terran proved stronger. One minute had ticked into another, more and more of her strength drained, until she stopped fighting entirely. She even lost her grip on her bag. Earlier she’d mentioned medicine. He doubled back, grabbed the pack and hefted it over his shoulder, but she offered no thanks. The feisty mortal had grown quiet, as well. At this rate, she would freeze to death before he reached his bunker. Rifters? He glanced at his right hand. Good to go. Rifters were made of a crystal-metal hybrid and resembled open-ended thimbles. They fit over the first, second and third fingers, and stretched from the nail bed to the middle knuckle. When you clinked them together, they vibrated. When they vibrated, you could wave them through the air to cut a doorway to somewhere else on Terra. You had…