Bewildered, Engel followed him into an office and looked through spacious windows down at the spires of a city he had never known. Beside a desk sat a wizened old man whose yellowed skin drawn taut over his broad skull gave him a shriveled, cadaverous aspect. He tapped a blue card on a thumbnail as his luminous eyes followed Engel suspiciously. "Doctor Weeve, my chief alienologist," Marston said. "Sit down, Engel." Engel grasped the arms of his chair as Dr. Weeve scrutinized the card in silence. "Jeffrey Engel," he read aloud in a high petulant voice. "Missing Persons Bureau, eh? Hmm, reminiscent of the twentieth century. Is that what you call your detective agency?" _Reminiscent of...._ Engel pressed shaky fingers to his throbbing head. If he told them he was from out of the past, how would they react? "Yes," he lied, "I found a fountain pen--" "You lone wolves have extraordinary hunches to compensate for a lack of police techniques," Dr. Weeve said with a dry chuckle. "But one needs protection when tracking aliens." "Tracking aliens?" Engel said, mystified. Marston laughed, leaned over his desk, and twirled a fountain pen in pudgy fingers. "Take it easy, you're not suspect in this case. But the report says you found this pen and in attempting to return it to its owner, you were struck by some invisible force." Marston glanced at Dr. Weeve who nodded, then his voice grew hard. "Did this C. G. aim anything at you before you were hit?" "No, he didn't," Engel said and touched his head nervously. "Headache?" Dr. Weeve asked. "No, it's nothing," Engel countered. "When I got up, the man was gone." "You mean the alien was gone," Dr. Weeve contradicted him. Engel's throat went dry and he stared at them. "An alien!" shouted Marston. "Don't you understand?" Dr. Weeve smiled thinly. "Mr. Engel's curious to learn the latest about them and would draw us out in this childish way. I assure you we despise them far more than millions who only read about them in their daily telescripts. Since the flying saucer crash in '68, we've been very much aware of their close surveillance of this world." The doctor's face clouded as he gazed at the city. "The filthy blue spawn of Centauri send us exceedingly clever spies. Before invading our cities, they must seek out our military installations and plant explosives at key points. Their assassins must be ready to strike...." Dr. Weeve gently wrung bony hands, and Marston leaned forward, his pale jowls quivering angrily. "To safeguard public welfare, this city branch of Alien Detection must find and exterminate aliens. So far we can boast of a perfect record, thanks to the new detection screen." Aliens? Engel winced, recalling the mournful little stranger. "I can't believe that he--" "That he's a humanoid?" Marston spat out the word as if it were a lump of vileness in his throat. "C. G.'s a sneaking saboteur who conceals his ugly blue hide under a layer of false skin! But he's been detected."