Option 3. There was no Option Three.

Tally simulated a human sigh, made up his mind, and angled for the nearest opening in the disk. He shot inside, feeling a sharp tug from the membrane at the entrance, and at once became aware of a difference. His suit’s thrustor — at last — was working as it was supposed to work. He slowed down rapidly, and smashed into the inner wall with no more than a bruising collision.

His pseudo-pain circuits cut in, but all they offered was a stern warning to take good care of his valuable body. Tally ignored that, and turned to look around for Hans Rebka.

And there he was! No more than twenty meters away in a big, curving chamber more stuffed with furnishings and equipment than any room that Tally had ever seen.

He turned toward Rebka. In fractions of a millisecond, he became aware of several strange facts.

First, Hans Rebka was no longer wearing a suit of any kind. Second, there were three of him, all female. And third, not one of the three was Hans Rebka.

The three women did not seem at all surprised by his arrival.

“Two months,” the shortest one growled, as soon as Tally was out of his suit. She was black-haired, big-muscled — a female version of Louis Nenda. Tally guessed that she hailed from a high-gravity planet. “Nearly two damn months since we arrived here.”

“And twenty-one days since I came in to rescue them.” The second speaker, hawk-nosed and sharp-cheekboned, pulled a face at E.C. “Hell of a rescue, eh?”

“Not your fault,” the dark-haired woman said gruffly. “We were all fooled. Thought we’d cracked Paradox, all ready to go out big heroes.” She waved her hand at the pair of tiny exploration vessels hovering near the entrance to the chamber. “None of us had any idea that the damn thing was changing, so we might not be able to get out. Same for you, I guess.”

“Oh, no.” Tally had at their urging removed his suit. The chamber was filled with breathable air and felt a little on the chilly side of pleasant. Gravity was low but not uncomfortably so. The women had somehow pulled fixtures from the walls, and were using them as furniture. The result was odd-looking, but formed a comfortable enough living area.

“We knew,” he went on. “Hans Rebka and I, we knew Paradox had changed.”

The three woman exchanged glances. “A right pair of Ditrons you two must be,” said the woman with the prominent cheekbones. “If you knew it had changed, why did you come in?”

“We thought it would be safe.”

The looks this time were a lot less veiled. “Actually,” Tally went on, “I did not enter because I thought it was safe. I knew it was not. I came in to rescue Hans Rebka.”

“That’s different.” The short, dark-haired woman shook her head. “Well, we sure know how that works. What happened to your buddy?”

“I have so far been unable to locate him.”

“Maybe we can work together.” The third woman, tall, blond, and skinny, waved a hand to Tally, inviting him to sit at a table constructed from two food cabinets laid on their sides. “I don’t normally think much of men, but this is a case where we need all the help we can get.”

“Ah.” E.C. Tally sat down carefully at the table, and lifted one forefinger. “In order to avoid a crucial misunderstanding, I should make one point perfectly clear. I am not a man. And now, to begin at the beginning—”

“Not a man?” The blond woman leaned across the table and gave Tally a careful head-to-toe inspection. “Not a man. You sure could have fooled me.”

“I am not a woman, either.”

The woman flopped down on the seat opposite Tally. “And I thought we were in trouble before. All right, we’ll do it your way. Begin at the beginning, like you said, and take your time. We’ve got lots — and it sounds like we’ll need all of it.”

Chapter Eighteen

Another half-day, and still no sign of J’merlia. Darya was worried. Kallik clearly was not. The little Hymenopt was systematically making three-dimensional reconstructions of the other five walls of the hexagonal chamber, using her new computer program on the images that Darya had made earlier.

She did not ask for help. Darya did not offer any. Each had her own obsessions.

Darya kept running the first picture sequence, over and over. All data on stellar velocities was back on board the Myosotis, and without that information she lacked an absolute means of measuring time. But the general pattern of the sequence was clear. Somewhere, far in the past and far from the worlds of the Fourth Alliance, an unidentified species had achieved intelligence and space flight. The spreading green points of light showed the stars that the clade had reached. Later, probably thousands of years later, another clade had escaped their home world and set off to explore and colonize. The second clade, judging from the location of the orange points of light, was the Zardalu.

They had spread also, speedily, aggressively. Finally they met and began to swallow up the worlds of the green clade.

So far, so good. Not much was known about the Zardalu expansion, but there was nothing in the display at variance with recorded history.

But now came a third clade, shown on the display in deep ruby-red. This one, according to its point of origin, represented humanity. It started out from the home world of Sol, and began a tentative spread outward. It never stood a chance. The expanding tide of Zardalu-orange caught and swallowed the first scattering of red points. It swept past Sol and on through the spiral arm, swamping everything else. Finally every green and red light was replaced by a point of orange flame.

That was the situation when the supergiant reference stars seemed to be in their present-day positions. Darya halted the progression of images. According to what she was seeing, the spiral arm was supposed to be, today, what it clearly was not: a region totally under Zardalu domination.

Darya stared and pondered. This was a picture of the spiral arm as it would have been had the Great Rising against the Zardalu never occurred. If the Zardalu outward drive had continued unchecked, every habitable planet of the spiral arm would have eventually come under the dominion of the land-cephalopods. The worlds of humans were gone, destroyed or confiscated. Humanity was enslaved or exterminated, together with all other species operating in space.

And the future?

There were more frames in the image sequence. Darya ran it onward. The stellar positions began to change again, to an unfamiliar pattern. Time advanced, by many thousands of years. But the pattern of color never altered. Every star remained a steady orange. Zardalu, and Zardalu alone, ruled. At last the orange points of light began to vanish, snuffing out one by one. The spiral arm became empty. It remained devoid of intelligent life, all the way to the final frame of the sequence.

Darya turned off the display in her helmet. She did not switch her visor to outside viewing. It was better to stare into blackness, and disappear into a maze of thought.

Here was not one mystery, but two.

First, how had Quintus Bloom been able to show on Sentinel Gate a realistic display of the spiral arm’s colonization — past, present, and future? He did not show the false pattern of Zardalu domination. Darya could not believe that he had invented that display. He had found it somewhere within Labyrinth, in this inner chamber, or more likely in some other of the thirty-seven.

Second, what was the significance of this display of spiral arm evolution, so clearly contrary to reality? The Builders were an enigma, but Darya could see no possible reason for them portraying on the walls of Labyrinth a fictitious history of the arm.