The professor looked at her. "Ah, child! Ever subtler, ever surer—the Eternal Enigma is no enigma to you."

"What is the Sphyx?" I asked.

"Have you read De Soto? Or Goya?"

"Yes, both. I remember now that De Soto records the Syachas legend of the Sphyx—something about a goddess—"

"Not a goddess," said Miss Barrison, her lips touched with a smile.

"Sometimes," said the professor, gently. "And Goya said:

"'It has come to my ears while in the lands of the Syachas that the Sphyx surely lives, as bolder and more curious men than I may, God willing, prove to the world hereafter.'"

"But what is the Sphyx?" I insisted.

"For centuries wise men and savants have asked each other that question. I have answered it for myself; I am now to prove it, I trust."

His face darkened, and again and again he stroked his heavy brow.