About half an hour later, the door he couldn't open slid aside into the wall. The man Maitland had seen outside, now clad in gray trunks and sandals, stood across the threshold looking in at him. Maitland stood up and stared back, conscious suddenly that in his rumpled pajamas he made an unimpressive figure. The fellow looked about forty-five. The first details Maitland noticed were the forehead, which was quite broad, and the calm, clear eyes. The dark hair, white at the temples, was combed back, still damp from swimming. Below, there was a wide mouth and a firm, rounded chin. This man was intelligent, Maitland decided, and extremely sure of himself. Somehow, the face didn't go with the rest of him. The man had the head of a thinker, the body of a trained athlete--an unusual combination. Impassively, the man said, "My name is Swarts. You want to know where you are. I am not going to tell you." He had an accent, European, but otherwise unidentifiable. Possibly German. Maitland opened his mouth to protest, but Swarts went on, "However, you're free to do all the guessing you want." Still there was no suggestion of a smile. "Now, these are the rules. You'll be here for about a week. You'll have three meals a day, served in this room. You will not be allowed to leave it except when accompanied by myself. You will not be harmed in any way, provided you cooperate. And you can forget the silly idea that we want your childish secrets about rocket motors." Maitland's heart jumped. "My reason for bringing you here is altogether different. I want to give you some psychological tests...." "Are you crazy?" Maitland asked quietly. "Do you realize that at this moment one of the greatest hunts in history must be going on? I'll admit I'm baffled as to where we are and how you got me here--but it seems to me that you could have found someone less conspicuous to give your tests to." Briefly, then, Swarts did smile. "They won't find you," he said. "Now, come with me." * * * * * After that outlandish cell, Swarts' laboratory looked rather commonplace. There was something like a surgical cot in the center, and a bench along one wall supported several electronics cabinets. A couple of them had cathode ray tube screens, and they all presented a normal complement of meters, pilot lights, and switches. Cables from them ran across the ceiling and came to a focus above the high flat cot in the center of the room. "Lie down," Swarts said. When Maitland hesitated, Swarts added, "Understand one thing--the more you cooperate, the easier things will be for you. If necessary, I will use coercion. I can get all my results against your will, if I must. I would prefer not to. Please don't make me." "What's the idea?" Maitland asked. "What is all this?"