The eighth book of the Dray Prescot series. Dray Prescot, the Earthman who had been brought across interstellar space as the tool of the mysterious Star Lords, confronted his most baffling task while he was a hunted and harried wanderer of the continent of Havilfar. That task was to discover the means by which the aircraft of that continent's most advanced civilization operated. Prescot is no scientist, but fulfill his task he must or he would never return to the princess and homeland he had won. So, for Dray Prescot there was but one course -- with a whole continent against him, with time itself conspiring to balk him, the secrets of an unknown science must be made his...