Carolus the stonecutter was a tall man for Fanglith, or at least for the places I'd been-only a few inches shorter than me. Even with a bulging middle, he looked extremely strong. He scowled at us as we came in.

"You're late," he snapped to Reyno.

"Yes sir. I met this young gentleman and brought him with me. His name is Larn. He has an interesting proposition-one that could be profitable."

The stonecutter's dark little eyes moved to me and stayed for a few seconds before he said anything more. My jumpsuit looked a lot different from clothes in Provence or Normandy, or any I'd seen at any rate. For a shirt, they generally wear a thing resembling a loose jacket that covers the upper legs. They call it a tunic. Instead of pants, most of the men wear a sort of leggings, with a kind of undershorts-more of a diaper, actually-to cover their genitals. None of it really fits. Also, the shoes don't have separate soles, and they don't press shut around the foot. Instead, they have a leather thong you draw them snug with and then tie. "Where are you from?" Carolus asked me. So there it was. I was going to have to tell him something, and it had to be a lie-hopefully, one that wouldn't trip me up. Remembering my one-night lecture on the world of Fanglith from Brother Oliver, more than two years earlier, I answered "India." India was a place that everyone had heard of and apparently no one had been. Things that were said about it sounded pretty imaginative.

His eyes had paused at my crucifix. "You're Christian."

"Yes. Although I've not been thoroughly instructed in it."

He shrugged. I'd already learned that most Christians hadn't been. "What is this interesting proposition?" he wanted to know.

"I'm a master calculator," I said. "Reyno tells me that the swiftest calculator in Marseille is a man named Isaac ben Abraham. I am faster at difficult calculations than he can possibly be, and perhaps at simple ones too. It seems to me we could have a contest, he and I, and there could be wagers. Whoever bet on me would win. In reward, I would get part of their winnings."

Carolus looked thoughtful. "You have not seen the Jew at his abacus; he is lightning swift. He is a man late in middle years, who was calculating long before you were born."

This kind of conversation would lead nowhere. "You have a slave who does your calculations," I said. "Is he fast?"

"Faster than most. But not so fast as the jew." "Let's see how much faster I am than your slave." For just a moment Carolus stood examining me. Then he turned toward a staircase that led upstairs through a raised trapdoor. "Faid!" he bellowed. "Down here!"

A few seconds later a slender, dark-complected man came down the stairs. He might have been thirty or thirty-five. "Yes, my lord?"

"I have need of your calculations."

"Yes, my lord." Faid walked over to a table beneath one of the windows. Carolus, Reyno, and I followed. There Faid sat down, and with one hand drew a sort of open-topped small box to him, a box with rows of beads on what seemed to be thin wooden rods. He looked questioningly at Carolus.

"Do a difficult problem," Carolus said to him, "but do not say from what roots, or what the answer is."

For just a moment Faid looked puzzled, then shrugged. His fingers moved quickly, the beads clicking for a few seconds. "It is done."

Carolus turned to me. "Where is your abacus?" he asked.

I took out my communicator, which was also a microcomputer, and switched it on. "Here," I answered.

He turned to Faid. "State your roots," he said.

"Twenty-eight fourfold."

"One hundred twelve," I answered. I didn't need my computer for that.

Carolus's eyebrows raised slightly and he turned to Faid. "Is that right?" he asked.

"Exactly right." The Saracen looked at me with considerable interest. "And what are the portions if you divide 144 into 18 equal parts?" His fingers raced as he asked it.

"Nine each," I said. "I need no abacus for that." Our math teachers in lower school had drilled us thoroughly. It looked as if this was going to be easy.

Faid looked up at Carolus. "He is right." Then he turned to me. "What sort of question would cause you to use your abacus?"

"Oh, the square root of some large number. Do you know how to do square roots?"

Faid nodded. "In the main they are problems for geometers. I can do them, but it takes time."

"Fine," I said. "Calculate a large square; that'll be easier. Then tell me what the square is and I'll give you its roots."

"Stand away then," he answered, "so you cannot see what roots I use."

We moved a few steps away and I turned my back to him. After a short while he said: "The square is 1,369."

I tapped 1,369 into the computer and asked for the square root. "The root is 37," I said, and turned to look at him. It had taken me about two seconds, which was about half as long as Paid stared at me before he said anything again.

"That is correct." He sounded impressed, or maybe awed would be more like it. "You must be Indian."

Carolus pursed his lips, then made a decision. "Paid, mention this to no one. None of it. How fast he is, that he comes from India, none of it. And you, Reyno: Keep that glib mouth shut, or I'll see you tongueless." Then he turned to me. "What is your name again?"

"Larn."

"Larn," he said, "we have things to talk about."

Carolus sent Reyno to Isaac ben Abraham, inviting him to contest with "a youth who is truly marvelous at calculations." Ben Abraham answered in writing, which Faid read to his master; reading was something else the Saracen could do and Carolus couldn't. After commenting that it was unimportant to him whether someone else could calculate faster or not, ben Abraham said it would amuse him to take me on. He offered to bet fifty gold bezants or an equivalent in Pisan solidi.

Carolus the stonecutter was a careful man who would bet only what he could afford to lose, even when it seemed almost certain that he wouldn't. And he felt very uncomfortable at the thought of betting fifty bezants. He sent back word that he would bet only twenty. Reyno had almost nothing of his own to bet, but borrowed two bezants from his master, Carolus was grumpy about lending it, and I suspect he only did it to keep Reyno from trying to borrow elsewhere and being questioned. He felt uneasy about word of the contest getting out.

Ben Abraham, smelling Carolus's uncertainty, decided he could probably beat me, and got Carolus up to thirty against his own sixty. Then, in amusement, he agreed to cover Reyno's small bet at odds of three to one. All of this was arranged through Reyno as courier.

Carolus was to pay me a sixth, or ten bezants, if I won. I wasn't sure what he'd try to do if I lost, but I couldn't see any chance of that happening.

The contest was to take place in the office of Isaac ben Abraham, shortly after the hour called "sext"-local midday, as far as I could tell. After eating an early lunch, we walked there through spring sunshine. I was impressed by ben Abraham's offices. They were clean, and there were decorative woven cloths called tapestries on some of the walls.

I was even more impressed with Isaac ben Abraham. He was the biggest man I'd seen yet on Fanglith, and the tallest except for a Norman knight named Brislieu. Besides which, he looked as if, under the fat, he'd be very strong physically. His face went with an age of about fifty or fifty-five, but his long black hair had only scattered threads of gray. He also had a bigger, thicker beard than I'd ever imagined, and wore the richest clothes, topped by a long, far-trimmed, brown velvet cape. All in all, when he spoke in his rich bass voice, people were likely to pay attention.

And it was obvious that he washed, he and the man who ushered us into his office. I'd never seen a clean Fanglithan before. I hadn't realized there were any.