"They didn't accomplish time-travel," Camhorn said, "though in theory they should have. I know it because we have several machines based on the same principles. The earliest was built almost eighty years ago. Two are now designed to utilize the YM thrust. The Trelawney machine is considerably more advanced in a number of details than its Overgovernment counterparts, but it still doesn't make it possible to move in time."
"Why not?"
"I'd like to know," Camhorn said. "The appearance of it is that the reality we live in takes the same dim view of time-travel that you do. Time-travel remains a theoretical possibility. But in practice—when, for example, the YM thrust is applied for that purpose—the thrust is diverted."
White looked bewildered. "But if Paul Trelawney didn't move through time, what did he do?"
"What's left?" Camhorn asked. "He moved through space, of course."
"Where?"
Camhorn shrugged. "They penetrated Riemann space," he said, "after harnessing their machine to roughly nineteen thousand times the power that was available to us before the Ymir series of elements dropped into our hands. In theory, Lolly, they might have gone anywhere in the universe. If we'd had the unreasonable nerve to play around with multikilograms of YM—knowing what happened when fractional quantities of a gram were employed—we might have had a very similar experience."
"I'm still just a little in the dark, you know," Laillard White observed drily, "as to what the experience consisted of."
"Oh, Lieutenant Dowland's theory wasn't at all far off in that respect. It's an ironic fact that we have much to thank the Trelawneys for. There's almost no question at all now what the race of beings they encountered were responsible for the troubles that have plagued us in the use of YM. They're not the best of neighbors—neighbors in Riemann space terms, that is. If they'd known where to look for us, things might have become rather hot. They had a chance to win the first round when the Trelawneys lit that sixty-eight kilogram beacon for them. But they made a few mistakes, and lost us again. It's a draw so far. Except that we now know about as much about them as they've ever learned about us. I expect we'll take the second round handily a few years from now."