"Are there any great collections of books in Trebizond?" Fra Tomasso leaned forward intently, and his belly, swathed in the white linen robe of his order, pushed the small black writing desk toward Daoud. Fra Tomasso's dialect was easy for Daoud to understand. It was the same as Lorenzo's, since the friar came from southern Italy. It was the dialect Daoud had learned in Egypt. But in another sense, conversing with d'Aquino was not at all easy. His body tense, Daoud sat on the edge of his chair, alert for any question that might be meant to trap him. And at the same time, he burned for a chance to persuade the stout Dominican to oppose the Tartar alliance. He was both hunted and hunter today. "Yes, Father. The basileus of Trebizond--the emperor--has the biggest library, with the monks of Mount Gelesias not far behind. Several of the great families have large collections of very old manuscripts. I am afraid I cannot tell you what is in any of those libraries. I know more about spices and silks than I do about books. Is there a particular book you are interested in?" Daoud, relieved, watched the round face glow as the Dominican seemed to relish the possibilities. It would never have done to admit it to Ugolini, but Daoud was not without fear. He realized that a slip might lead to his arrest and torture, the end of his mission, and, finally, death. His head had begun to ache from the effort of posing and answering all questions with care. But now he sensed a way of reaching d'Aquino. More than anything else, the man would want books--books that would help him write more books of his own. Perhaps his huge physical appetite was but a reflection of his hunger for knowledge. "Ah, Messer David." He smiled, and Daoud realized that his mouth was not small--it only looked small because of the round cheeks on either side of it. "There is one book I have heard of that I would give everything I possess--if I possessed anything--to own. You are familiar with _the_ philosopher, Aristotle?" Daoud nodded. How wise it had been of Baibars, he thought, to command him to spend months with a mullah from Andalus who was versed in the philosophies of the Christians and of their Greek and Roman predecessors. Daoud had even read works by Aristotle in Arabic. "Much of my work, like that of my colleagues, is based on the writings of Aristotle," d'Aquino went on. "He has been called the Master of Those Who Know. I call him _the_ philosopher. His thought encompassed every subject under the sun--and the sun itself, I believe. The ancient writers refer to a book by Aristotle called in Latin _De Caelestiis, Of the Heavens_. In it _the_ philosopher writes about the movement of heavenly bodies, the sun, the stars, and the planets, and their relations with one another. That book disappeared during the long wars that led to the downfall of the Roman Empire. Every time I meet a traveler from some distant part of the world, I ask him about _De Caelestiis_."