"It is called cryptic, I'll remind you, because the victim makes a very determined and intelligently executed effort to conceal his memory lapse--frequently shutting himself up for several days on some pretext and feverishly studying all materials and documents relating to himself he can lay hands on. Undoubtedly sometimes he succeeds. The cases we hear about are those in which he makes such major slips--as being mistaken as to what his business is, who he is married to, who his friends are, what is going on in the world--that he is forced, against his will, to go to a psychiatrist. Whereupon, realizing that his efforts have failed, he generally confesses his amnesia, but is unable to offer any information as to its cause, or any convincing explanation of his attempt at concealment. Thereafter, readjustment is rapid." He looked around. "And now, gentlemen, a matter which the experts didn't bring out, because I arranged it that way. I have saved it in order to impress it upon your minds as forcibly as possible--the correlation between cryptic amnesia and delusions of nonrecognition." He paused with his hand near the box, aware that there was something of the conjurer about his movements and trying to minimize it. "I'm going to switch on both projections at once. Where cases of cryptic amnesia and delusions of nonrecognition coincide--I mean, where it is the cryptic amnesiac about whom the other person or persons had delusions of nonrecognition--the dots will likewise coincide; and you know what happens when violet and yellow light mix. I'll remind you that in ordinary cases of amnesia there are no delusions of nonrecognition--family and friends are aware of the victim's memory lapse, but they do not mistake him for a stranger." His hand moved. Except for a sprinkling of yellow, the dots that glowed on the map were pure white. "Complementary colors," said Clawly quietly. "The yellow has blanked out all the violet. In some cases one violet has accounted for a cluster of yellows--where more than one individual had delusions of nonrecognition about the same cryptic amnesiac. Except for the surplus cases of nonrecognition--which almost certainly correspond to cases of successfully concealed cryptic amnesia--the nonrecognitions and cryptic amnesias are shown to be dual manifestations of a single underlying phenomenon." He paused. The tension in the Sky Room deepened. He leaned forward. "It is that underlying phenomenon, gentlemen, which I believe constitutes a threat to the security of the world, and demands the most immediate and thorough-going investigation. Though staggering, the implications are obvious." * * * * * The tautness continued, but slowly Conjerly got to his feet. His compact, stubby frame, bald bullet-head, and uncompromisingly impassive features were in striking contrast with Clawly's mobile, half-haggard, debonair visage. Leashed anger deepened Conjerly's voice, enhanced its authority.