Tallen took one himself, then: "I understand your wife is working with hypersee." Parmay nodded. "Did you ever ask her why we can't get a line on the aliens' location?" "Sure. And I get the same answer I'd get if I'd asked you: 'I don't know.' Hypersee waves aren't directional. They seem to ignore normal space-time and the matter and energy in it. They probably aren't instantaneous, but they're so close to it that trying to measure their rate of propagation at ordinary interstellar distances is as futile as Galileo's experiment with the lanterns on the mountain-tops. Or was that Torricelli? Anyway, we don't have any way of knowing where they are or how far away." Tallen looked back at the alien on the screen. "Then Junior, here, might be on the other side of the galaxy, as far as we know?" "Right. Or M-33 in Andromeda. Or it's possible that they died out a thousand years ago, having lived at some spot in the universe so remote that even the hypersee hasn't reached us till now." Tallen looked incredulous. "Then why are we worrying, if the damned things might not be anywhere around? Just on the off chance that they might be?" Parmay shook his head. "Not exactly. We don't know anything from a strictly physical point of view, true; but we have done some work on the psychological side. We know, for instance, that they have seen our faces and heard our voices, just as you and I can watch Junior. We know this from the basic reactions of sentient creatures to that type of stimulus. They are aware of our existence. That rules out their being too far. "We've been working to get ahead of them for five hundred years. If they're on the other side of the galaxy, we have another five hundred years before we contact them; if they're in one of the nearer galaxies, it will be another two thousand years. "But we'll contact them eventually, and it had better be on even terms." Tallen examined the glowing end of his cigarette as though he were appraising a piece of art. "Too bad there isn't a doppler in hypersee; if the drive could be located, it would make it easy." He looked up at Parmay. "Do you know why we take so long to get to Therbis? Because of the stops. Look here." He picked up a card from the desk. "I use a table of random numbers. Every time we pass a star whose number is in the