"Who else can I talk to, besides you?"

"Carrolson. You can talk to her about everything but what you read in the libraries. I'm working to get her clearance for that, too. But not yet. You'll meet others in a couple of days. Some will have library clearance, and you'll be working with them, coordinating, cross-checking. Clear enough? For the next couple of weeks, it's going to be study, study, study."

"How far from the camp can I go?"

"As far as you can walk, but take along a radio. We have a security base about fifty kilometers down the corridor, with sensors set to pick up any activity in the corridor for several hundred kilometers. If they call a retreat, get back to the tunnel as soon as possible."

"What's the likelihood of that happening?"

"Small." Lanier shrugged. "Maybe nonexistent. Hasn't happened yet. I hope you don't resent kid-glove treatment. If anything happened to you, the Advisor would have new hairless rugs all over her floor."

Patricia grinned. "So who's my duenna?"

"Until Carrolson gets here, Farley. Questions?"

"Let me get started, then I'll ask questions."

"Fair enough." Lanier left her at the table. She picked up the slate and began the first memory block.

Chapter Six

Lanier left on the next shift, saying he would be back in two days to begin the next part of her education. Carrolson arrived a few hours later, carrying a box of memory blocks and a more powerful processor recently shipped from Earth. "At least I can take part of my work with me wherever I go," she said. Farley, Wu and Chang immediately began submitting some of their problems to the new processor.

Patricia studied the cubes that contained information on the corridor. The length of the corridor was unknown, but radar signals sent from the bore hole had not yet returned after the passage of four months. It was assumed that either the corridor had no end or that the signals had been absorbed in some as-yet-unexplained way.

Exploration teams had made several forays into the corridor, but until recently, none had proceeded farther than five hundred kilometers. To that point, the corridor was indistinguishable from the seventh chamber it adjoined: a thick layer of dirt, atmosphere at Stone-normal pressure—650 millibars—and the normal intensity of flux tube lighting.

The corridor differed from the seventh chamber in one respect: 436 kilometers down the line, it was surrounded by a circuit of artificial structures, four motionless cupolas floating without support above wide dimples in the soil. Each of the four cupolas stood alone, spaced at equal distances from the others around the circumference. What they were made of was unknown, but the substance didn't match any of the characteristics of matter except for solidity. Eight hundred seventy-two kilometers down the line was another circuit, and a new expedition was exploring in that area now.

Patricia tapped the slate's burnisher against her tooth, then reached into her personal effects bag and brought out the stereo attachment and a coin of Mozart. The attachment lifted easily in the standardized socket and played The Magic Flute as she read on, undisturbed.