"You can't. Mawson's knowledge of this Carol can easily be turned to your disadvantage. He can use her to lead you to dissolution in there. No, it's much too risky. You're lucky you got out when you did." "But what about Mawson, then?" * * * * * Burgess tried to look confident. He failed. "We can ring up your headquarters and ask for another man. Or, if worse comes to worse, we can partition off this part of the hospital, and just sit it out until Mawson runs out of atomic building blocks." "Which may take years," Jerry reminded him. Burgess turned his palms upward. "What else can we do?" "Send me again," said Jerry. "I know the score pretty well, now. I know what to watch out for. I'm sure that with one more try I can get Mawson out of there." "Sorry," Burgess said, shaking his head. "As a medical man, I cannot permit it. You've had a bad shock. We'll try someone else, if your outfit will send someone, and see what happens. If he fails, or if they won't supply us with any more men, then--well, you can try again in a few weeks, if you're still game. But not now." "Doctor, in a few weeks, Mawson will be so well in control of that universe that he may find a way to block the entrance. Have you thought of that?" "His universe is not a real one--" Burgess began. "But that duplicator is real enough. It can make anything he decides he needs. And at any time he may get the bright idea of simply mounting his machine right at the entrance, so anyone stepping into that gray field will be powdered into atoms, instantly." "That's true enough," admitted Burgess. "But my diagnosis still stands. For now, you are off this assignment. When I feel you're ready--assuming nothing else has succeeded meantime--I'll contact you at the base." "How do you know I won't be off on some other planet by then?" asked Jerry bitterly. "I don't," said Burgess. "I hope you are not, but there isn't anything further I can do about it. I'm sorry." "And what do I do in the meantime?" Burgess grinned. "Call up this Carol and go out on the town." Jerry shook his head at the last part. "No thanks. I prefer Carol to know nothing about it." Burgess shrugged and gave it up. "All right, Norcriss. Rest here till you feel stronger, then you're free to go." Then he was striding off down the corridor. After a bit, Jerry sat up cautiously, let the slight giddiness subside, then swung his legs off the side of the cart and got down. Behind him, the door to Mawson's universe stood open on its wall of grayness. Jerry stared thoughtfully at it, then saw that the two internes who were guarding the opposite ends of this section of the hospital corridor were hesitantly half-starting toward him. Jerry knew he could be through that doorway and into the grayness before they got within ten feet of him.... IV