“I am waiting.”

Outside Paradox, E.C. Tally crouched over the reel.

“Now!”

Tally moved the whole reel backward to increase the tension in the line, tentatively at first, then with steadily greater force. “Are you moving?”

“Not a micron. Pull harder, Tally. We have nothing to lose. Pull harder. Harder! Hard—”

E.C. Tally and the reel went shooting backward, turning end over end in space. Tally twisted to keep the line in sight. It was clearly free to move, whipping rapidly out of Paradox, meter after meter of it. It was also clear from its movement that there could be nothing substantial on the other end of it.

Hans Rebka was deep inside Paradox, as planned. Not as planned, he seemed to be stuck there.

The designers of E.C. Tally had done one other thing that must have seemed like a good idea at the time. It stemmed from their own conviction that an embodied computer could think better than a human.

It stood to reason. E.C. Tally had attosecond circuits, capable of a billion billion calculations a second. He could absorb information a billion times as fast as a human. He forgot nothing, once it was learned. His thinking was logical, unclouded by emotion or prejudice.

The designers had incorporated all that information into E.C.’s memory bank. It provided him with overwhelming confidence. He knew, with a certainty that no human could ever approach, that he was smarter than any organic mind.

And Hans Rebka had an organic brain.

Therefore…

The whole thought process within E.C. Tally occupied less than a microsecond. It took another microsecond for him to construct a message describing the entire sequence of events since their approach to Paradox. He went back to the ship, transferred the message at once to the main communications unit, and selected the Sentinel Gate coordinates for transmission through the Bose Network. He checked the node delays as the message went out. The signal would reach Sentinel Gate in four to five days. Darya Lang or Quintus Bloom, even if they received the message at once and set out immediately for Paradox, could not possibly arrive in fewer than ten days.

Ten days. Enough time for Hans Rebka to run low on air in his suit, but not really a lot of thinking time for a human’s slow brain.

But ten days was close to a trillion trillion attoseconds. Time enough for the powerful brain of an embodied computer to analyze any situation, and solve any conceivable problem.

E.C. Tally waited for the confirmation that his message was safely on its way to the first Bose Transition point. Then he set the ship’s controls so that it would hover a fixed distance from the surface of Paradox. He turned on the ship’s beacon, so that anyone approaching the artifact would be able to home in on it.

And then he went outside and turned to face the artifact.

E.C. Tally to the rescue!

He switched to turbo mode on his internal clock, set the suit for maximum thrust, and plunged into the iridescent mystery of Paradox.

Chapter Fourteen

Why Labyrinth?

Why not “Spinning Top” or “Auger” or “Seashell” or “Cornucopia”? That’s what the artifact resembled, turning far-off in space. Darya’s first impression had been of a tiny silver-and-black humming top, drilling its way downward. Closer inspection showed that Labyrinth stood stationary against its backdrop of stars. The effect of downward motion was created by Labyrinth’s form, a tapering coiled tube that spiraled through five full turns from its blunt top to its glittering final point. Imagination transformed that shape to the polished shell of a giant space snail, many kilometers long. A row of circular openings spaced regularly around the broadest part of the shell appeared and disappeared as Labyrinth rotated.

Or, according to Quintus Bloom, seemed to rotate. Darya glanced from the artifact to the notes and back again. Anyone examining Labyrinth from the outside would be sure that this was a single three-dimensional helix, narrowing steadily from top to bottom and rotating in space around a central axis. The openings appearing and disappearing around its upper rim merely confirmed what was obvious to the eye.

Obvious, and wrong, according to Bloom. Labyrinth did not rotate. Bloom reported that laser readings reflected from the edges of Labyrinth showed no sign of the Doppler shift associated with moving objects. The openings on the upper edge moved around the perimeter; yet the perimeter itself was stationary.

Darya performed the laser measurement for herself, and was impressed. Bloom was right. Would she have sought to confirm what appeared to be a totally obvious rotation by an independent physical measurement, as he had done? Probably not. She felt awed at his thoroughness.

Darya returned again to the study of Bloom’s notes. They had occupied her since she and her companions left the surface of Jerome’s World. Each of the thirty-seven dark openings in Labyrinth was an entry point. Moreover, according to Bloom, each one formed an independent point of entry and led to an interior unique to each. The thirty-seven separate interiors were connected, one to another, through moving “windows,” rotating inside Labyrinth just as the outside openings rotated. An explorer could “cross over” from one interior to another, but there was an inexplicable asymmetry; if the explorer tried to return through the same window, the result was an interior region different from the original place of departure.

Quintus Bloom had done his best to plot the connectivity of the inside, and had produced a baffling set of drawings. Darya puzzled over them. The problem was, every connection point in Labyrinth was moving, so every portal from a given interior might lead to any one of the other thirty-six possible regions. And as one descended into the tighter parts of the spiral, the region-to-region connections changed.

She decided that Bloom was right again, this time in his naming of the artifact. Labyrinth was better than any snail or spinning-top analogy.

Which entry point should she use from the Myosotis? In the long run it might not matter; every interior could lead to any other. But the “pictorial gallery” of the spiral arm that Quintus Bloom had described might be present in only one of the regions. It was not at all obvious which one they wanted, or that they could reach it by at most thirty-six jumps through a moving door. The region-to-region linkages probably depended, critically, on timing.

Darya stared at a plot of scores of cross-connection notations recorded by Quintus Bloom, and struggled to visualize the whole interlocking system. Here was a mental maze, a giant gastropod merry-go-round in which different layers turned — or seemed to turn — at different speeds: thirty-seven co-rotating and interacting three-dimensional Archimedean spirals, sliding past each other. It was like one of those infuriating math puzzles popular at the Institute, where the trick to the solution was a translation of the whole problem to a higher number of dimensions. Twice Darya felt that she almost had it, that she was on the point of grasping the whole thing in her mind as a coherent entirety; twice it slipped away. Like so many things associated with the Builders, the interior of Labyrinth seemed to surpass all logic.

She decided there was one acceptable answer: Close your eyes. Pick an entry point. And get on with it, playing the hand you were given.

Darya emerged from her reverie over that problem, and at once faced another. She must make a decision she had been putting off since leaving Jerome’s World. Someone must remain aboard the Myosotis. Who?

It was unfair to ask Kallik or J’merlia to enter Labyrinth. They had not chosen this mission, and any new artifact could be dangerous. That argued for Darya, and Darya alone, to make a visit to the interior. Unfortunately, Kallik had her own intense interest in Builder artifacts, and a knowledge of them that matched Darya’s. She was quite fearless, and would want to be part of any exploration party. As a final point, Kallik’s years with Louis Nenda had given her more practical experience than Darya.