We have examined with interest the information that you have sent to us. We are happy to inform you that, thus far, you have satisfied the requirements for membership in the Perpetual Order of Seekers After Truth. Before accepting new members into this ancient and honorable secret society, we find it desirable that they have a personal interview with the Grand Chairman of POSAT. Accordingly, you are cordially invited to an audience with our Grand Chairman on Tuesday, July 10, at 2:30 P.M. Please let us know if this arrangement is acceptable to you. If not, we will attempt to make another appointment for you. The time specified for the appointment was hardly a convenient one for Don. At 2:30 P.M. on most Tuesdays, he would be at work in the laboratory. And while his employers made no complaint if he took his research problems home with him and worried over them half the night, they were not equally enthusiastic when he used working hours for pursuing unrelated interests. Moreover, the headquarters of POSAT was in a town almost a hundred miles distant. Could he afford to take a whole day off for chasing will-o-wisps? It hardly seemed worth the trouble. He wondered if Betty would be disappointed if he dropped the whole matter. Since the letter had been sent to the laboratory instead of his home, he couldn't consult her about it without telephoning. _Since the letter had been sent to the laboratory instead of his home!_ But it was impossible! He searched feverishly through his pile of daily mail for the envelope in which the letter had come. The address stared up at him, unmistakably and fearfully legible. The name of his company. The number of the room he worked in. In short, the address that he had never given them! "Get hold of yourself," he commanded his frightened mind. "There's some perfectly logical, easy explanation for this. They looked it up in the directory of the Institute of Physics. Or in the alumni directory of the university. Or--or--" But the more he thought about it, the more sinister it seemed. His laboratory address was available, but why should POSAT take the trouble of looking it up? Some prudent impulse had led him to withhold that particular bit of information, yet now, for some reason of their own, POSAT had unearthed the information. His wife's words echoed in his mind, "Could they be a spy ring? Subversive agents?" Don shook his head as though to clear away the confusion. His conservative habit of thought made him reject that explanation as too melodramatic. At least one decision was easier to reach because of his doubts. Now he knew he had to keep his appointment with the Grand Chairman of POSAT. He scribbled a memo to the department office stating that he would not be at work on Tuesday. * * * * *