"C. D.?" Engel echoed. C. D.? C. G.? C. D.? The initials hopped wildly about in his mind. At a soft whistling sound he glanced up above a high hedge and his eyes widened. Gleaming white towers rose up to fade into misty blue, and around them silently darted silvery bubbles. Faintly traced with jointed, concentric lines, the sky seemed to curve over him like a lofty and enormous spider web. As he was pulled across a wide street, tall, hollow-cheeked people stopped to stare at him, and he stared back in wonder. "Who are they?" Engel faltered. The cop said nothing and led him through the low entrance of a tower. As they went down a glowing hall, Engel touched the back of his still aching head. Was his fall in the park causing these hallucinations? Possibly. But before the fall, hadn't some mysterious, unseen force thrown him into this crazy world? Then he had to find it again and somehow escape back to reality! * * * * * They entered a large room where lines of gaunt, solemn people stood gravely before grill windows. _The Enemy is Listening!_ a sign on a wall warned him as a loudspeaker blared out a garbled message. The cop shoved him into a line. Finally the man ahead of them fidgeted up to an ugly, hatchet-faced woman who frowned impatiently. "Yes?" she snapped. "My wife deserted me," the scarecrow of a man complained. "I want to--" "Fill out this form, drop it in slot 9," she rapped out. "Next?" "A drunk and robbery suspect," the cop said. "Here's the evidence." Brightening, Hatchet-Face snatched up the fountain pen and whisked out a blue card. "Misdemeanor and felony," she breathed sharply. "I'll take the details." Engel clung to the edge of the window counter as the interrogation began. Yes, he told them, he actually believed something invisible had knocked him down after swallowing up the stranger. No, he hadn't robbed the stranger, he wasn't confessing anything. Yes, he was an honest citizen with no previous criminal offenses. After more probing questions and vicious jabs at the form, she handed it to the cop who dropped it in a nearby wall slot. They waited for a verdict. In a moment the cop turned to Hatchet-Face who whispered with him excitedly. Flushed and triumphant, he steered Engel out into the hall. "Alien Detection wants you," he growled with uneasy respect. * * * * * They got into an elevator and shot swiftly upward. As they stepped into a lavish reception room filled with sickeningly sweet perfume, a scrawny, over-rouged girl shut a magazine and jumped to a switchboard. Then a door opened, and a short, puffy man with cold fish-eyes bounced up to them. Waving the cop away, he gripped Engel's hand. "Ah, Mr. Engel!" he said smiling. "I'm Commissioner Marston. Sorry about the mix-up, but we didn't realize you were after C. G. Come in, please."