"And what will you give us?" she asked.

"Your colleagues will have their choice of returning to Earth or proceeding down the Way with the Geshels. You, on the other hand, will be given the means to play out your dream."

"My dream?"

Ry Oyu walked to a smooth black cabinet under the center of the shimmering cupola. He opened the cabinet and brought out a small pearl-white box. Returning, he held the box to Patricia and instructed her to open it.

She lifted the lid. Within, lying in a hollow of green velvet, was a miniature version of the clavicle that depended from the scaffold. Yates looked upon it with her and sighed.

"We're offering you an exchange, a trade in which you lose nothing," Ry Oyu said. "You let us copy your Mystery, to complete the Engineer's personality record, and we will let you search for your home."

"You're saying that my soul, and Korzenowski's, are identical?" Patricia asked.

"'Soul' is an imprecise term," the gate opener said. "'Mystery' at least has the advantage of a more precise application. When everything in a personality—memory, thought patterns, skills—has been abstracted out, the sum of their parts is still not the whole. There is a super-pattern which colors the entire psyche, and which can be lost when even the great majority of fragments are reassembled. This is called the 'Mystery.' We have never been able to synthesize it. It is ineffable, and it can only be transferred by an imposition of all the patterns of one person on the assembled personality fragments of another. What is already present in the other is rejected; what is not present, the Mystery, is retained. That is the gift you could give to us—to Korzenowski."

She took hold of Lanier's hand, suddenly afraid. This was not in the same league with the things that had gone before; it seemed abruptly mystical and unconvincing. For a time, she had thought that nothing could remain unknown to these descendants, and yet here it was, primary and basic; elaborated upon, manipulated, but not solved.

"You could take it from me by force," she said. "Why try to convince me?"

"Force is not useful in these circumstances," Ry Oyu said. "Either you give voluntarily or you do not give at all."

"Why do you want him back? Hasn't he served his purpose?"

"It's a matter of honor." Olmy smiled. "If the Knights of the Round Table could have brought King Arthur back, don't you think they would have? The Engineer must see that his plan has come to fruition."

"But not as he expected."

"No," Olmy admitted.

Patricia looked down at her clasped hands. "Do I lose anything?"

"No," the gate opener said patiently.

"And in exchange, I get to use this. . . .” She pointed to the miniature clavicle. "Why is it so small?"

"It has been deactivated," Yates said.

"It's yours?"

He nodded.