Meanwhile the displaced mind, thrown back to the displacer’s age and body, would be carefully guarded. It would be kept from harming the body it occupied, and would be drained of all its knowledge by trained questioners. Often it could be questioned in its own language, when previous quests into the future had brought back records of that language. If the mind came from a body whose language the Great Race could not physically reproduce, clever machines would be made, on which the alien speech could be played as on a musical instrument. The Great Race’s members were immense rugose cones ten feet high, and with head and other organs attached to foot-thick, distensible limbs spreading from the apexes. They spoke by the clicking or scraping of huge paws or claws attached to the end of two of their four limbs, and walked by the expansion and contraction of a viscous layer attached to their vast ten-foot bases.
When the captive mind’s amazement and resentment had worn off, and when (assuming that it came from a body vastly different from the Great Race’s) it had lost its horror at its unfamiliar temporary form, it was permitted to study its new environment and experience a wonder and wisdom approximating that of its displacer. With suitable precautions, and in exchange for suitable services, it was allowed to rove all over the habitable world in titan airships or on the huge boat-like atomic-engined vehicles which traversed the great roads, and to delve freely into the libraries containing the records of the planet’s past and future. This reconciled many captive minds to their lot; since none were other than keen, and to such minds the unveiling of hidden mysteries of earth — closed chapters of inconceivable pasts and dizzying vortices of future time which include the years ahead of their own natural ages — forms always, despite the abysmal horrors often unveiled, the supreme experience of life.
Now and then certain captives were permitted to meet other captive minds seized from the future — to exchange thoughts with consciousnesses living a hundred or a thousand or a million years before or after their own ages. And all were urged to write copiously in their own languages of themselves and their respective periods; such documents to be filed in the great central archives.
It may be added that there was one sad special type of captive whose privileges were far greater than those of the majority. These were the dying permanent exiles, whose bodies in the future had been seized by keen-minded members of the Great Race who, faced with death, sought to escape mental extinction. Such melancholy exiles were not as common as might be expected, since the longevity of the Great Race lessened its love of life — especially among those superior minds capable of projection. From cases of the permanent projection of elder minds arose many of those lasting changes of personality noticed in later history — including mankind’s.
As for the ordinary cases of exploration — when the displacing mind had learned what it wished in the future, it would build an apparatus like that which had started its flight and reverse the process of projection. Once more it would be in its own body in its own age, while the lately captive mind would return to that body of the future to which it properly belonged. Only when one or the other of the bodies had died during the exchange was this restoration impossible. In such cases, of course, the exploring mind had — like those of the death-escapers — to live out an alien-bodied life in the future; or else the captive mind — like the dying permanent exiles — had to end its days in the form and past age of the Great Race.
This fate was least horrible when the captive mind was also of the Great Race — a not infrequent occurrence, since in all its periods that race was intensely concerned with its own future. The number of dying permanent exiles of the Great Race was very slight — largely because of the tremendous penalties attached to displacements of future Great Race minds by the moribund. Through projection, arrangements were made to inflict these penalties on the offending minds in their new future bodies — and sometimes forced re-exchanges were effected. Complex cases of the displacement of exploring or already captive minds by minds in various regions of the past had been known and carefully rectified. In every age since the discovery of mind-projection, a minute but well-recognised element of the population consisted of Great Race minds from past ages, sojourning for a longer or shorter while.
When a captive mind of alien origin was returned to its own body in the future, it was purged by an intricate mechanical hypnosis of all it had learned in the Great Race’s age — this because of certain troublesome consequences inherent in the general carrying forward of knowledge in large quantities. The few existing instances of clear transmission had caused, and would cause at known future times, great disasters. And it was largely in consequence of two cases of the kind (said the old myths) that mankind had learned what it had concerning the Great Race. Of all things surviving physically and directly from that aeon-distant world, there remained only certain ruins of great stones in far places and under the sea, and parts of the text of the frightful Pnakotic Manuscripts.