While the Empress of Earth was between destinations, she dipped at regular intervals from sponge space back into the sidereal universe. The vessel's artificial intelligence compared a blink of a wedge of the visible stars against that synthesized from the data base as existing at that point in space. If the two star charts varied, the AI adjusted the attitude and burn of the fusion engines for the next sponge space insertion. For the human bridge crew, the process was as boring as rereading a telephone directory.
The engines themselves could not be insulated from the series of sponge-space bubbles as the interior of the Empress was. Their thrust had to be delivered in sponge space, using the varied constants of those other universes in order to multiply the vessel's movements against the sidereal universe.
The men who serviced the engines could work only in the sidereal universe, but they had to remain on the hull throughout their watch. Sending them in and out at each extraction would have multiplied the vessel's transit time. For those men, the Cold Crews, the navigational extractions provided brief minutes of normalcy—albeit hard vacuum and hard work—to punctuate the in-pressing madness of universes to which mankind and life itself were alien.
"Oh, all right, Etcherly," Bruns said. Mid-watch boredom made him lethargic, unwilling to look at anything new even though he had nothing better—indeed, nothing at all—to do. "What is it that you've got?"
Etcherly murmured a command. Her console echoed its data onto Bruns's. She was projecting the chart of the most recent navigation check. "It's just . . ." she said. "There's an anomaly. In the upper right quadrant—"
A red carat on the display noted the point of light—one of literally hundreds of thousands at this degree of detail.
Before responding, Bruns ran the chart—the realtime display—against the computed synthesis of what the chart should have looked like. Red carats lit all across the display. When the Second Officer corrected for navigationally significant levels of accuracy—10-17—the carats disappeared.
Except for the one Etcherly had noted.
Bruns shrugged. "Right," he said. "It's an anomaly. One bit of space junk that's too small to be entered in the data base. It's a big universe, Etcherly, but it's not so big that we're going to have it completely to ourselves every time we come out of sponge space."
Donaldson, the helmsman, didn't move while Bruns and the navigating tech were speaking. His eyes were open, but Bruns sometimes had the impression that the helmsman was capable of sending his soul light years away until recalled by an unexpected requirement or the end of his watch.
"Yessir," said Etcherly, "but see—"
The displays, hers and Bruns' together, flickered through the whole run of navigational checks since the watch began three hours previously. The star charts differed wildly from one to the next. Not only were the glimpses separated by great distances, but also the shortest transit through bubbles of sponge space traced a path in no particular order through the sidereal universe. The only constant in the varying stellar panoramas was the anomaly carated in the upper right-hand quadrant.
"Oh," said Bruns. "That's odd."
He rubbed his lips with the knuckles of his right hand. "It's either a problem with the sensors, or a problem with the data base. Frankly, neither one thrills me."
"Bridge says the hardware's okay," Etcherly said. "It says the software's okay, too, but I guess it would. I mean, if there's a problem, it's a problem with Bridge, isn't it?"
Officer and technician stared at one another. The red marks on their displays pulsed softly in unison.
"It's a ship," said Donaldson unexpectedly. He didn't turn his head in the direction of either of the others on the bridge.
"That's impossible!" Bruns snapped. "We've been in and out of sponge space forty times this watch. We couldn't possibly have matched courses so closely with another vessel."
"The lifeboats," Etcherly said, staring at the display in sudden surmise. "Could one of them have been picked up when we jumped from Tellichery?"
"No," Bruns said flatly. He rubbed his mouth again. "We weren't within ten-to-the-twelfth meters when we made the initial insertion. Besides, you don't just 'pick things up' when you insert into sponge space."
He shrugged. "It's a fault in the system and my money's on the sensors, whatever Bridge has to say about it. We'll get it taken care of on Tblisi, they've got full docking facilities. But it's not a serious problem."
"It's a ship," Donaldson repeated. "It's matching course with us. And it's getting closer."