Gibson shrugged. "I know the Bees always erected domes on every planet they colonized, Arthur, but precedent is a fallible tool. And it's even more firmly established that there's no possibility of our rationalizing the motivations of a culture as alien as the Hymenops'--we've been over that argument a hundred times on other reclaimed worlds." "But this was never an unreclaimed world," Farrell said with the faint malice of one too recently caught in the wrong. "Alphard Six was surveyed and seeded with Terran bacteria around the year 3000, but the Bees invaded before we could colonize. And that means we'll have to rule out any resurgent colonial group down there, because Six never had a colony in the beginning." "The Bees have been gone for over a hundred years," Stryker said. "Colonists might have migrated from another Terran-occupied planet." Gibson disagreed. "We've touched at every inhabited world in this sector, Lee, and not one surviving colony has developed space travel on its own. The Hymenops had a hundred years to condition their human slaves to ignorance of everything beyond their immediate environment--the motives behind that conditioning usually escape us, but that's beside the point--and they did a thorough job of it. The colonists have had no more than a century of freedom since the Bees pulled out, and four generations simply isn't enough time for any subjugated culture to climb from slavery to interstellar flight." Stryker made a padding turn about the control room, tugging unhappily at the scanty fringe of hair the years had left him. "If they're neither Hymenops nor resurgent colonists," he said, "then there's only one choice remaining--they're aliens from a system we haven't reached yet, beyond the old sphere of Terran exploration. We always assumed that we'd find other races out here someday, and that they'd be as different from us in form and motivation as the Hymenops. Why not now?" Gibson said seriously, "Not probable, Lee. The same objection that rules out the Bees applies to any trans-Alphardian culture--they'd have to be beyond the atomic fission stage, else they'd never have attempted interstellar flight. The Ringwave with its Zero Interval Transfer principle and instantaneous communications applications is the only answer to long-range travel, and if they'd had that they wouldn't have bothered with atomics." Stryker turned on him almost angrily. "If they're not Hymenops or humans or aliens, then what in God's name _are_ they?" * * * * * "Aye, there's the rub," Farrell said, quoting a passage whose aptness had somehow seen it through a dozen reorganizations of insular tongue and a final translation to universal Terran. "If they're none of those three, we've only one conclusion left. There's no one down there at all--we're victims of the first joint hallucination in psychiatric history."