The absence of a stir among his listeners was more impressive than any stir could have been. Clawly noted that Conjerly's frown had deepened, become almost angry. He seemed about to speak, when Tempelmar casually forestalled him.
"I don't think telepathy can be counted out as an explanation," said the tall, long-featured, sleepy-eyed man. "It's still a purely hypothetic field—we don't know how it would operate. And there may have been contacts between Thorn's subjects that he didn't know about. They may have told each other their nightmares and so started a train of suggestion."
"I don't believe so," said Clawly slowly. "His precautions were thorough. Moreover, it wouldn't fit with the reluctance of the dreamers to describe their nightmares."
"Also," Tempelmar continued, "we still aren't a step nearer the underlying cause of the phenomenon. It might be anything—for instance, some unpredictable physiological effect of subtronic power, since it came into use about thirty years ago."
"Precisely," said Clawly. "And so for the present we'll leave it at that—vastly more frequent nightmares with strangely similar landscapes, cause unknown—while I"—he again gauged the position of the dawn-line—"while I hurry on to those matters which I consider the core of our case: the incidence of cryptic amnesia and delusions of nonrecognition. The latter first."
Again Conjerly seemed about to interrupt, and again something stopped him. Clawly got the impression it was a slight deterring movement from Tempelmar.
He touched the box. Some hundreds of yellow dots appeared on the World Map, a considerable portion of them in close clusters of two and three.
He said, "This time, remember, we can't go back any fifty years. These are such recent matters that there wasn't any hint of them even in last year's Report on the Psychological State of the World. As the experts agreed, we are dealing with an entirely new kind of mental disturbance. At least, no cases can be established prior to the last two years, which is the period covered by this projection."
He looked toward the map. "Each yellow dot is a case of delusions of nonrecognition. An otherwise normal individual fails to recognize a family member or friend, maintains in the face of all evidence that he is an alien and impostor—a frequent accusation, quite baseless, is that his place has been taken by an unknown identical twin. This delusion persists, attended by emotional disturbances of such magnitude that the sufferer seeks the services of a psychiatrist—in those cases we know about. With the psychiatrist's assistance, one of two adjustments is achieved: the delusions fade and the avowed alien is accepted as the true individual, or they persist and there is a separation—where husband and wife are involved, a divorce. In either case, the sufferer recovers completely.