Thane stepped over to the map. He pointed to the Onzarian Confluence. "O.K. There's our bottleneck. But where's the cork? Just how do you figure on stopping a fleet if it does surface at the Onzarian Confluence for two or three microseconds?" Pyuf slapped the butt of his cigarette across the tray on Reine's desk. "There, Agent Thane, we reach the point of the whole show. But let's get the story straight from the source." His eyes went to Reine. Reine, pouring his second cup of coffee, looked up. "If you mean me, that's not very accurate. It's true that it was developed in my laboratory but Astrid was the one who saw the hint, originally, and did all the development. I'm not even familiar with all the details." He smiled apologetically to Thane. "We're talking about the Tracer. As a by-product of our main job we discovered a new way of plotting warp-lines. Instead of doing it by mathematics we found a way of plotting warps directly by instrument. Well, I was on the main line of research, and I had three times as much as I could do already. I just regarded this as a curiosity. But Astrid took it and built the Tracer." Pyuf interrupted. He was not the man, Thane saw, who could abide technical explanations when they had a clear political implication. "The Tracer," he said, "is the cork for your bottleneck. With the tracer, we know when any ship is operating on second-stage drive. With two tracers, separated on a baseline of a few million kilometers, we can plot position closely. Three tracers will pin-point them, and for a trip across the center of the Galaxy, we will know when and where they'll have to surface." "That fits all right," Thane said, "but why tie in Onzar? Why not let the Allied Systems have the tracer?" Pyuf shrugged impatiently. "Gentlemen, from here on, we need a drink. The explanation is simple, limpid, computable logic. As far as we can see, it's the only course." He stared pointedly at Thane. "But it also could be construed as treason. So we'd better have a drink." He stepped to the door. "Astrid, will you bring glasses and the bottle? We've got a bit of dialectics to dispense with." * * * * *