"What is a spring?" I asked.

"A narrow leaf of thin metal, wound into a tight coil by this key." He showed me the key, then used it to sketch a small, tight spiral in the earth at our feet. "That is what the spring looks like, and every arcabucero carries a key." He inserted his into a hole in what he had called "the lock," turned the key a time or two, and I heard a faint grating noise. "There, the wheel is ready to spin. Now, this thing here we call a cat's-paw." It was another small metal piece, not like a cat's paw at all, but shaped more like a bird's head, gripping in its beak a bit of gravel. "That stone," the soldier explained, "is a pirita." And I recognized it as a tiny fragment of what we call the "false-gold."

"Now, we cock the cat's-paw back, ready to strike," he went on, thumbing it backward with a click, "and another spring holds it there. Then—observe—I squeeze the kitten, the wheel spins and at the same instant the cat's-paw slaps its pirita against the wheel and you will see a spray of sparks."

Which is exactly what occurred, and the soldier looked more proud than ever.

"But," I said, "there was no flash or noise or smoke from the tube."

He laughed indulgently. "That is because I had not yet loaded the arcabuz or primed its cazoleta."

He produced two large leather pouches and, from one of them, dribbled a small pile of dark powder into my palm. "That is the pólvora. See, now I pour a measured amount of it down the mouth of the cañon here, and shove in behind it a small piece of cloth. Then, from this other pouch, I take a cartucho." He showed me a small, transparent sac—like a bit of tied-off animal intestine—packed with little metal pellets. "For shooting enemies or large animals, of course, we use a heavy round bala. But for birds we use a cartucho of perdigones." Then, with a long metal rod, he tamped all the contents tightly down in there. "Last of all, I put a mere touch of the pólvora here on the cazoleta." That was a little pan sticking out shelflike from the lock, where the sparks from the wheel and the false-gold would strike it. "You will notice," he concluded, "that there is a narrow hole going from the cazoleta into the cañon where the charge of pólvora is packed. Now, here, I wind the spring and you squeeze the gatillo."

I knelt down to the charged weapon with commingled curiosity, timidity and dread. But the curiosity was foremost, because I had come here and accosted the young soldier with precisely this end in mind. I put my finger through the guard beneath the arcabuz's lock, hooked it around the kitten and squeezed.

The wheel spun, the cat's-paw snapped down, the sparks sprayed, there was a noise like an angry little snarl and a puff of smoke from the powdered pan... and then the arcabuz rocked backward, and I flinched wildly away, as its mouth roared and spewed a flame and a bloom of blue smoke and, I had no doubt, all those death-dealing metal pellets. When I had recovered from the shock and the ringing in my ears, the young soldier was laughing heartily.

"¡Cáspita!" he exclaimed. "I will wager that you are the first and only indio ever to fire such a weapon. Do not let anyone know that I let you do it. Come, you can watch me load all the arcabuces for the next fusillade."

As I followed him, I said, "Then the pólvora is the absolute essential component of the arcabuz. The lock and wheel and cats and such are simply to make the pólvora work as you wish it to."

"Indeed, yes," he said. "Without the pólvora there would be no firearms at all in the world. No arcabuces, granadas, culebrínas, petardos. Ni siquiera triquitraques. Nada."

"But what is the pólvora?" I asked. "What is it made of?"

"Ah, now that I will not tell you. It was rash enough of me to let you play with the arcabuz. The orders are that no indio be allowed to handle any weapon of the white men, and my punishment for that would be dire. I certainly cannot reveal the composition of the pólvora."

I must have looked downcast, because he laughed once more and said, "I will tell you this much. The pólvora is obviously very much a man's property, for manly uses. But, oddly enough, one of its ingredients is a very intimate contribution from the ladies."

He went on laughing as he went on working, and as I drifted away. He took no notice of my departure, nor had he noticed that the small amount of the pólvora he had poured into my hand had gone into my own belt pouch, nor that I had picked up one of the wheel-winding keys I found lying beside one of the other arcabuces.

Bearing those items, I made my way to the Cathedral—hurrying thence, before I might forget any detail of the contrivances I had been shown. It was past the hour of Compline when I got to Alonso's workroom, so the notarius was not there, probably busy at his devotions. I found a blank piece of bark paper and, with a stick of charcoal, began to draw: the kitten and its guard, the cat's-paw, the wheel, the spiral of spring...

"Are you returned to work late this evening, Juan Británico?" said Alonso, coming through the door.

I managed not to jump or act startled. "Only practicing some word-pictures of my own," I said offhandedly, crumpling the paper but holding on to it. "You and I do so much translating of other scribes' work that I feared I might be forgetting the craft. So, having nothing better to do, I came back here to practice."

"I am glad you did. I would like to ask you something."

"A su servicio, Cuatl Alonso," I said, hoping I did not look wary.

"I have just come from a meeting of Bishop Zumárraga, Archdeacon Suárez-Begega, the Ostiarius Sánchez-Santoveña and various other custodians. They are all agreed that it is time the Cathedral was provided with more dignified and resplendent furnishings and vessels. We have been using makeshift paraphernalia only because a whole new Cathedral must be built before long. However, since such articles as chalice and monstrance, pyx and stoup—even larger things, like a rood screen and a font—can be easily moved to the new building, it has been agreed that we procure all those things, and of a quality befitting a Cathedral."

"Surely," I said, "you are not seeking my agreement?"

He smiled. "Hardly. But you may be of assistance, since I know you wander widely about the city. These fixtures and appurtenances must be of gold and silver and precious gems. Your people used to be sublimely accomplished at such works. Before we send a crier through the streets, calling for a master jewelsmith to come forward, I thought you might be able to suggest someone."

"Cuatl Alonso," I said, gleefully clapping my hands together, "I know the very man."

Back at the mesón, I said to Pochotl, "You are acquainted with the Spanish weapon we call the thunder-stick?"

"The arcabuz, yes," he said. "At any rate, I have seen what it can do. One of them put a hole—as if it had thrown an invisible javelin—clear through my elder brother."

"Do you know how the arcabuz works?"

"How it works? No. How should I?"

"You are an artist of great ingenuity. Could you make one?"

"Make a device that is both outlandish and prodigious? A thing I have seen only from a distance? Without even knowing how it works? Are you tlahuéle, friend, or merely xolopítli?"