"Eureka, little fellow! She's down to where I can't read it, even on this big gauge--so hard that it won't need flashing--harder than any vacuum I ever got on Tellus, even with a Rodebush-Michalek super-pump!" "But how about occluded and absorbed gas in the filaments and so on when they heat up?" demanded Nadia, practically. "All gone, ace. I out-gassed 'em plenty out there--seven times, almost to fusion. There isn't enough gas left in the whole thing to make a deep breath for a microbe." He took up his welding projector and a beam carried him back to the tube. There, in the practically absolute vacuum of space, the last openings in the glass were sealed, and man and great transmitting tube were wafted lightly back into the Terrestrial cruiser. Hour after hour mirrored Titanian sphere and crude-fashioned terrestrial wedge bored serenely on through space, and it was not until Titan loomed large beneath them that the calm was broken by an insistent call from Titan to the sphere. "Barkodar, attention! Barkodar, attention!" screamed from the speakers, and they heard Barkovis acknowledge the call. "The Sedlor have broken through and are marching upon Titania. The order has gone out for immediate mobilization of every unit." "There's that word 'Sedlor' again--what are they, anyway, Steve?" demanded Nadia. "I don't know. I was going to ask him when he sprung it on us first, but he was pretty busy then and I haven't thought of it since. Something pretty serious, though--they've jumped their acceleration almost to Tellurian gravity, and none of them can live through much of that." "Tellurians?" came the voice of Barkovis from the speaker. "We have just...." "All x--we were on your wave and heard it," interrupted Stevens. "We're with you. What are those Sedlor, anyway? Maybe we can help you dope out something."