turned off the motor. Coghlan nodded and went into the courtyard below his windows. He felt a very peculiar dogged anger, and was not at all certain what he felt it toward. He headed for the stairway to his apartment. Across the flagstoned courtyard, a plump figure came disconsolately out of that stairway. It was Appolonius the Great. He was not twinkling as usual. He looked desperately worried. But his expression changed at sight of Coghlan. "Ah, Mr. Coghlan!" he said delightedly. "I thought I had missed you!" Coghlan said politely: "I'm glad you didn't. But I'm only here on an errand--" "I need only a moment," said Appolonius, beaming. "I have something to say which may be to your advantage." "Come along," said Coghlan. He led the way. Appolonius, a few hours back, had looked as deeply concerned as any man could look. Now he appeared more nearly normal. But he was still not his usual unctuous self. He came toiling up the stairs with his customary smile absent as if turned off by a switch. When Coghlan opened the door for him, however, the smile came back as if the same switch had been turned again. Coghlan had a sudden startled feeling that Appolonius might be dangerous. "Just a moment," he said. He went into the bath and washed out the small cut and put antiseptic on it. It was not much deeper than a scratch, but he wanted to avoid a scar if possible. A scar would mean that the fingerprint on that seven-hundred-year-old page of sheepskin was authentic; was actually his. And he was not willing for that to be true. He came back into the living-room to find Appolonius sitting in a chair on the far side of the room from the open windows. "Now I'm at your service," said Coghlan. "That was a bad business today--about Mannard." Appolonius looked at him steadily, with a directness and force that was startlingly unlike his usual manner. "I have information," he said evenly. "May I show you my information?" Coghlan waited. "I am a professional illusionist," said Appolonius, that odd force now in his voice. "Deceptions are my profession. My fame is considerable." "So I've heard," agreed Coghlan. "Of course," said Appolonius, "I do not use all my knowledge of illusion on the stage. Much of it would be lost upon theatrical audiences." His voice changed, became deliberately sarcastic. "In my native country there is a superstition of evil spirits. The Magi--the priesthood--the holders of the traditions and lore of--ah--Neoplatonism, make use of this belief. They foster it, by driving away numerous evil spirits. The process is visible. Suppose I assured you that there was an evil spirit in this very room, listening to our talk?" "I'd be a trifle doubtful," said Coghlan gently. "Allow me," said Appolonius politely, "to demonstrate." He glanced about the