"Yes. The sector I was on is really quite advanced, for an electro-chemical civilization. That weapon I brought back with me--that solid-missile projector--is typical of most Fourth Level culture. Moving parts machined to the closest tolerances, and interchangeable with similar parts of all similar weapons. The missile is a small bolt of cupro-alloy coated lead, propelled by expanding gases from the ignition of some nitro-cellulose compound. Most of their scientific advance occurred within the past century, and most of that in the past forty years. Of course, the life-expectancy on that level is only about seventy years." "Humph! I'm seventy-eight, last birthday," the boyish-looking pilot snorted. "Their medical science must be mostly witchcraft!" "Until quite recently, it was," Verkan Vall agreed. "Same story there as in everything else--rapid advancement in the past few decades, after thousands of years of cultural inertia." "You know, sir, I don't really understand this paratime stuff," the pilot confessed. "I know that all time is totally present, and that every moment has its own past-future line of event-sequence, and that all events in space-time occur according to maximum probability, but I just don't get this alternate probability stuff, at all. If something exists, it's because it's the maximum-probability effect of prior causes; why does anything else exist on any other time-line?" Verkan Vall blew smoke at the air-renovator. A lecture on paratime theory would nicely fill in the three-hour interval until the landing at Dhergabar. At least, this kid was asking intelligent questions. "Well, you know the principal of time-passage, I suppose?" he began. "Yes, of course; Rhogom's Doctrine. The basis of most of our psychical science. We exist perpetually at all moments within our life-span; our extraphysical ego component passes from the ego existing at one moment to the ego existing at the next. During unconsciousness, the EPC is 'time-free'; it may detach, and connect at some other moment, with the ego existing at that time-point. That's how we precog. We take an autohypno and recover memories brought back from the future moment and buried in the subconscious mind." "That's right," Verkan Vall told him. "And even without the autohypno, a lot of precognitive matter leaks out of the subconscious and into the conscious mind, usually in distorted forms, or else inspires 'instinctive' acts, the motivation for which is not brought to the level of consciousness. For instance, suppose, you're walking along North Promenade, in Dhergabar, and you come to the Martian Palace Cafe, and you go in for a drink, and meet some girl, and strike up an acquaintance with her. This chance acquaintance develops into a love affair, and a year later, out of jealousy, she rays you half a dozen times with a needler." "Just about that happened to a friend of mine, not long ago," the pilot said. "Go on, sir."