“Admittedly the stars are far thicker than appears. My instruments can detect none beyond a few parsecs. But what data I’ve gathered of late leads me to suspect the estimate of a quarter million total is conservative. To be sure, most are dwarfs—”

“Come off that!” Laure barked. “I don’t need you to explain what I knew the minute I saw this place.”

“You need to be drawn out of your fantasizing,” Jaccavrie said. “Though you recognize your daydreams for what they are, you can’t afford them. Not now.”

Laure tensed. He wanted to order the view turned off but checked himself, wondered if the robot followed that chain of his impulses too, and said in a harshened voice: “When you go academic on me like that, it means you’re postponing news you don’t want to give me. We have troubles.”

“We can soon have them, at any rate,” Jaccavrie said. “My advice is to turn back at once.”

“We can’t navigate,” Laure deduced. Though it was not unexpected, he nonetheless felt smitten.

“No. That is, I’m having difficulties already, and conditions ahead of us are demonstrably worse.”

“What’s the matter?”

“Optical methods are quite unsuitable. We knew that from the experience of the Kirkasanters. But nothing else works, either. You recall, you and I discussed the possibility of identifying supergiant stars through the clouds and using them for beacons. Though their light be diffused and absorbed, they should produce other effects—they should be powerful neutrino sources, for instance—that we could use.”

“Don’t they?”

“Oh, yes. But the effects are soon smothered. Too much else is going on. Too many neutrinos from too many different sources, to name one thing. Too many magnetic effects. The stars are so close together, you see; and so many of them are double, triple, quadruple, hence revolving rapidly and twisting the force lines; and irradiation keeps a goodly fraction of the interstellar medium in the plasma state. Thus we get electromagnetic action of every sort, plus synchrotron and betatron radiation plus nuclear collisions, plus—”

“Spare me the complete list,” Laure broke in. “Just say the noise level is too high for your instruments.”

“And for any instruments that I can extrapolate as buildable,” Jaccavrie replied. “The precision their filters would require seems greater than the laws of atomistics would allow.”

“What about your inertial system? Bollixed up, too?”

“It’s beginning to be. That’s why I asked you to come take a good look at what’s around us and what we’re headed into, while you listen to my report.” The robot was not built to know fear, but Laure wondered if she didn’t spring back to pedantry as a refuge: “Inertial navigation would work here at kinetic velocities. But we can’t traverse parsecs except under hyperdrive. Inertial and gravitational mass being identical, too rapid a change of gravitational potential will tend to cause uncontrollable precession and nutation. We can compensate for that in normal parts of space. but not here. With so many stars so closely packed, moving among each other on paths too complex for me to calculate, the variation rate is becoming too much.”