And all the time, the turmoil in Dane's brain continued ... a chaotic, inarticulate fumbling, based on some point of confusion between the two names, _John_ and _Clark_. But despite the pain, Dane hardly noticed the groping and the searching. He had mind only for the colored light and changing shape of the weird crystal that hovered before him. For there was only one thing it could be: a Kalquoi, one of those dreaded alien invaders who'd long since usurped the outer planets, beyond the asteroid belt. Now it was here, on this ship, headed straight for Mars! And there was nothing he could do about it. As if to emphasize the point, the amoeboid monster in whose grip he lay pushed a new pseudopod down upon Dane's head and face. Oozing, enveloping, smothering, it pressed into every pore and orifice. Dane gasped for breath that would not come. Choking, jerking, convulsing, he struggled against the mucilaginous mass that held him. It was like fighting quicksand. The creature would not let him go. Fire raced through Dane's lungs. Black fog rose, clouding his consciousness. He forgot who he was, and where he was, and even the pulsing pain of the Kalquoi's sentient probings. Slowly, then faster and faster, he began to fall ... to fall.... Only then, of a sudden, his mouth and nose, his face, were clear again. Spasmodically, Dane sucked air into his lungs in great, anguished gasps. When his knees gave way, he slumped to the slime-slick floor. It dawned on him dimly, then, that the monster had left him ... that he was free and safe once more. Why? Still not quite steady, he looked out across the bem-tank; saw the protoplasmic horror huddled in a quaking, quivering mass against the chamber's far wall. The Kalquoi hovered above it; and when the giant amoeba-thing made a tentative effort to ooze back in Dane's direction, the alien assailed it with sudden, darting light-beams that seared deep into the pseudopodal creature's tissue. The demonstration was enough for Dane: the Kalquoi had saved him. But again, why? It was a question without an answer--or, at least, with no answer Dane himself could fathom. Besides, for now, it was enough that he remained alive. Puzzles could come later. Meanwhile-- But before he could organize the thought, sound came into the tank's stillness: the creak of screw-locks turning; the clink of a spring catch released. For the barest instant the Kalquoi hovered as if listening. Then, like a candle snuffed out, it vanished. Dane surged to his feet. Darting across the slippery decking, he found the yat-stick and, snatching it up, stuffed it out of sight beneath his tunic. Simultaneously, a sudden draft told him the hatch was open. Light blazed--a brilliant beam that pinned Dane, half-blinded, to the tank's wall. Yet in spite of his situation, he could not repress a momentary grin. It would be worth a good deal of discomfort just to watch Pfaff's reaction when he found victim alive and monster cowed!