In fire and thunder it was born, vomited up from the guts of the earth in a paroxysm of fury.

Cooled. Broken. Moved. Lost. Buried.

Only for a time. It was a fragment of the divine, and the gods had sent it to the world of mortals for a purpose. It hungered to fulfill that purpose.

Stone is patient. Hidden in its cocoon, the obsidian butterfly waited to become.

The new ground of the milpa stood out like a wound torn into the forest. Without the protective canopy of the trees, the sun blazed hard upon the earth. After the seeds were planted, Konil would have to pile up leaves to keep the soil from being scorched dry, killing the treasure it held.

He’d shared the backbreaking work of clearing this field with the other aluxob of the village. No little alux, no matter how tough-bodied, could cut down and haul away the trees on his own. But now that the milpa was ready, he did the planting alone: pacing off the rows, piercing the ground with his digging stick, burying the red and gold kernels of maize that would feed his family—he hoped. His harvests had been thin for years now, his wife and six daughters reduced to menial work in exchange for seed corn. But the black earth of the new milpa was soft and rich, and perhaps it would yield abundance. Enough to lure a husband for his eldest daughter, who had reached an age for marriage. Then Konil would no longer work alone.

Step, bend, thrust, place, cover. A familiar trance—until his stick hit something hard, just below the surface.

Konil winced at the small shock. Laying aside the stick, he scraped the soil away with his calloused fingers, exploring the thing he’d struck.

A stone. And when his thumb wiped the dirt from its surface, it gleamed.

Konil’s breath caught. Surely not... He spat onto the stone and wiped again, this time with the kerchief that bound the soft puff of his hair. The barkcloth left behind a smooth, glassy expanse.

“Obsidian,” he whispered.

The instant the word escaped his lips, he twisted to look around, as if someone might have heard. But no: he was still alone in the forest, except for the raucous call of a bird, like a warning cry.

Obsidian. The stone was unmistakable; not even the finest flint could mimic its sheen. The local motherfather had a small obsidian knife, shorter than one of Konil’s fingers, for use in sacrifices. It had come all the way from Tepatiliztlan, because the priests and nobles of the city controlled the supply and bestowed it according to their will.

Hunching over the stone, Konil searched for its edges. His stubby fingers scrabbled through the soil, burrowing through more and more dirt, heedless of the milpa and his seeds. At last his questing thumb sank past the stone, and a sharp sting told him he’d found an edge. Konil curled his blood-slicked fingers around his prize and pulled carefully.

Soil cascaded as it came up, revealing its full size at last. Konil sank back and laid it across his lap. The oblong was longer than his two outstretched hands laid tip-to-tip. Aluxob had small hands, but still... it was a treasure of unspeakable value.

What strange accident had brought it there? Konil had found stones in his milpas before, but never obsidian. That came from the highlands, many days to the east, where the mountains gave it birth. And such a large piece...

The how and why didn’t matter. Only the stone itself mattered, the simple fact of its presence.

It was a gift from the gods.

One for which he’d already shed blood. Konil added a whispered prayer of thanks to his offering. Then he abandoned his digging stick there in the milpa, abandoned his seeds and his water, and hurried home with the stone wrapped in leaves and his barkcloth cape. His wife was out, working in the weaving-house, but he sent his youngest daughter to fetch her, without saying why.

That night they huddled by the soft light of the fire, talking in hushed whispers.

“Great honor, for whoever brings it to the nobles in the city,” his wife said. She had refused to touch the stone, but she stared unblinking at its glossy surface, gleaming in the light. “Honor enough to bring husbands for all our daughters.”

She was right. But Tepatiliztlan lay many days’ journey away, and he was a mere alux, a simple farmer who knew nothing of the road. “The trader is here. If we sold it to him—” In exchange for what? Mere cacao beans couldn’t fix his family’s situation. That would buy him seed corn, yes, but not a fertile field. They needed honor, something to lift them above their low state for good. That meant going to the city himself.

“You must convince the trader to take you with him,” his wife said.

She had beautiful eyes, green as new leaves, but tonight the firelight painted them gold, hiding the meaning behind her words. Convince. Bribe. But how? The trader was a vay sotz, a creature of the merchant caste. He would drive a hard bargain, and Konil didn’t even have cacao beans to pay him with. What offering could they make to the trader that would persuade him to help?

Konil closed his eyes. Perhaps his wife had already seen it. Not cacao beans; not turquoise or gold or carved bone, none of which he had anyway. Something intangible, something even a family as poor as his could offer.

And even the wealthiest of traders might desire.

The obsidian waited on the hearth, cocooned in barkcloth and leaves, holding the promise of the future. But only if they paid its price.

“Chachal,” he said at last, opening his eyes. Light flared as a log cracked and the fire leapt up. “She is the only one old enough. And her husband will not care, when he marries the daughter of the alux who found the stone.”

His wife did not protest, nor even murmur in shock. She understood the necessity as well as he did.

“Wake her,” Konil said. His heart felt like a rock within his chest: not holy obsidian, but common stone, dirty and ugly. “We must take her to see the trader tomorrow. And she deserves to hear the truth before she goes.”

Jachanel’s people moved swiftly through the forest despite the heavy burdens they carried, balanced on their backs with tumplines across their foreheads to take the weight. Even the little alux farmer carried a basket, despite his small size; no sense wasting a pair of feet, even if he wasn’t of the merchant caste.

And after the price Konil had paid for this escort, Jachanel was hardly going to argue over a basket. The daughter was sweet as a berry. Maybe not much of a beauty, compared with the carved jades of Tepatiliztlan, but delightfully modest. She didn’t even weep. Jachanel hadn’t been cruel; he simply took what her father offered, in fair payment for his aid.

But there was something else about the farmer—something secret. Konil should have known better than to try and hide something from the sharp eyes of a vay sotz. Not for nothing did the lords of the cities hire members of Jachanel’s caste as spies. Their merchant duties took them everywhere, and they missed nothing.

The little farmer had hidden something in the bottom of his basket, and Jachanel intended to find out what it was.

When they stopped for the night, Jachanel offered to heat up the atolli. For everyone else he mixed the toasted cornmeal with water and ordinary spices, but the cup he prepared for Konil held something else as well. He carried it to Konil himself and crouched, bringing his lanky height down to the alux’s level. “Here. You’re not used to walking all day.”

Konil accepted the cup gratefully. “I work hard every day. But yes, walking is different. The road hurts my feet.”

“It will be worse tomorrow,” Jachanel said truthfully. “Get what rest you can tonight.”

He would get plenty of rest. The soporific in his atolli was strong, meant for the physicians in Tepatiliztlan; Konil would have slept through the death of the sun. The alux had laid his blanket far from the others—as far as he could get without risking the dangers of the forest—and so Jachanel had both leisure and privacy to unpack his basket.

Most of it was filled with the cargo Jachanel had assigned him to carry. There was a cape and a second loincloth, not much finer than the first, and a small corn-husk doll probably given to him by one of his daughters. But at the very bottom, he found something much heavier, wrapped tight in a barkcloth cocoon.

From the weight alone, his long, bony fingers identified it as stone. Some precious jade? An idol, perhaps? Jachanel pulled back the wrappings, eager to find out.

Obsidian, rough and black as the night around him.

And worth more than Jachanel’s entire cargo of cotton and polychrome vases.

In the morning, Konil’s blanket was empty. “That’s what comes of bringing a farmer among merchants,” Jachanel sighed. “They wander off in the night to take a piss, and before they know it, a jaguar has them.” Indeed, some of his guards had heard a jaguar in the night. The great cats preferred their prey live, but Jachanel imagined some lazy one had appreciated the easy pickings of a fresh corpse.

It wasn’t the first time they’d lost someone during the journey. His bearers shrugged and moved on.

The only inconvenience was that they had to reshuffle their packs to distribute Konil’s portion of the load. Jachanel made sure the barkcloth cocoon found its way into his own small pack. Compared to some of the burdens he’d carried, the stone was hardly anything, but he was aware of it with every step he took. With that stone, Tepatiliztlan’s artisans could make one of the great sacrificial knives—not the little slivers villagers used for ritual bloodletting and the slaughter of animals, but something worthy of the great temples and their rites. How great would Jachanel’s reward be for delivering such a treasure? He fancied that the stone whispered to him as he walked, promising a great house in the city, with slaves to tend him there, and no more trudging along the trails that joined one flyspeck village to another. It could bring him all that, and more.

But first he had to get it into the hands of the appropriate people.

In Tepatiliztlan Jachanel sold his cargo for cacao beans, instead of trading it for salt and other goods he could carry onward to the next city. Then, with the stone concealed beneath a pack full of beans, he climbed the steps to the palace mound where the priests and the artisans dwelt.

Many guards stood there, low-ranking ocelotlaca adorned with little more than coral and carved bone. “I come to visit an artisan of jade,” Jachanel said, and showed a handful of his cacao beans to prove that he could pay.

The guard who had stopped him was female, with broad shoulders beneath her bright fur. The jaguar-woman peered at him suspiciously. “What city were you in last?”

He knew better than to say “Iztlacatun,” given all the conflicts between the two domains. “Ohuiyotlan,” Jachanel said, thinking it safe—but the name was barely out of his mouth before a powerful, clawed hand clamped down on his shoulder and dragged him out of the entrance plaza, into a smaller room.

The guard ripped the pack from his shoulders and threw him to the floor. Without pausing, she upended the pack, letting out a cascade of cacao beans, and—“No!” Jachanel shouted, but it was too late; the barkcloth bundle fell after them.

It landed atop the beans and rolled. Snarling, the ocelotlacatl tore it open, shredding cloth and leaves alike with her claws. Then she stopped, staring at the gleaming blackness within.

Unharmed, despite its fall. Jachanel let out an unsteady breath of relief.

“So,” the jaguar-woman said. “Not a spy from Ohuiyotlan.”

Jachanel shook his head, swallowing a curse, and arranged himself on his knees. “I have brought this stone to Tepatiliztlan, so that it may bring the blessings of the gods upon the lord in her struggle against her enemies in Ohuiyotlan.” Whatever they had done to earn this kind of suspicion.

A low, rumbling growl came from the guard’s deep chest. “A treasure,” she said, and her claws tightened around the torn wrappings. Then she sighed. “But one that brings more trouble than it’s worth, I think—especially when I have another treasure here. Take your stone, little bat; take it to the motherfather Cenquiztli, and tell anyone who halts you that Nexicolli has said you may pass.” She shoved the obsidian back into his pack.

Jachanel took it, trembling, and not entirely understanding. “My cacao beans—”

The golden jaguar eyes gleamed. “My cacao beans,” Nexicolli said. “Payment for not leaving your entrails on this floor. I could take everything you have, even your life, for lying to me. Be glad I only take your wealth.”

He swallowed. An entire cargo’s value, scattered across the floor. But he had the stone, and that was worth more than all the rest of it.

“Thank you, noble warrior,” he said through his teeth, and slunk out of the room.

Cenquiztli was accustomed to the reactions of strangers. Few understood the decision of the lord to accept a xera within the bounds of the domain, and even fewer agreed with it. The vay sotz trader’s narrow, batlike shoulders shrank inward at the sight of Cenquiztli, and he hesitated in the entrance, as if afraid to enter.

“You are safe,” Cenquiztli said, with calm patience. “I am the motherfather of this domain, and no danger to you.”

One watched the vay sotz advance, unwilling, staring. No mask of flesh concealed one’s body; one openly displayed the rough-hewn wooden limbs that marked them as a xera, and—usually—outcast. That was part of one’s agreement with the lord. But the shape of that wooden body was Cenquiztli’s own doing: on the left side a curved breast and a rounded hip, on the right a broad shoulder and a flat belly. Motherfather: a title that recalled the original beings the gods had created, before gender, before caste, before everything. Many people could rise to the rank of that title, but only xera could create, in their own bodies, a shape that echoed that past.

Not easily. The opposition of the seasons touched everyone, but xera more clearly than anyone else. Cenquiztli’s form required the perfect balance of spirit: too much of the wet season, and one’s body would shift fully male. Too much of the dry, and one’s would be female.

What the vay sotz brought was a threat to that balance.

“I know what you carry,” Cenquiztli said, and watched the vay sotz flinch a second time, his bony fingers tightening around the tattered bundle. “Show it to me.”

The trader obeyed, kneeling and unknotting the ties that held the barkcloth tight. “My name is Jachanel. At great risk I have brought this from distant lands, through the domains of our lord’s enemies, keeping it safe from their eyes and their hands. I have beggared myself in the process, all so that I might present to the lord this treasure beyond price, this gift to please the gods.”

Cenquiztli gazed down upon the scarred blackness of the obsidian. A treasure beyond price: the trader was right. But he did not understand the truth of his own words.

He’d called it a gift. For Jachanel’s own sake, Cenquiztli would hold him to that.

“This comes to us in our day of need,” one said. “Set it on the floor.”

Jachanel obeyed.

“For this gift,” Cenquiztli said, “You have the gratitude of the mighty lord of Tepatiliztlan.”

The vay sotz waited, but Cenquiztli said no more.

“Motherfather,” he began, hesitantly.

“You wish a reward,” Cenquiztli said.

“I have beggared myself,” Jachanel repeated, and a note of fear entered his voice.

That part of his tale, Cenquiztli believed. He showed the panicked tension of someone who had never imagined walking out of here with nothing.

One knelt in front of the obsidian and raised a four-fingered hand over it, letting it hover like a hummingbird but not touching. “Of course you have. Obsidian requires sacrifice. When it takes its final shape, it will drink regularly of blood, bearing that most precious substance from the world of flesh into the world of spirit. But for it to transform, it must be nourished.”

Cenquiztli looked up, meeting Jachanel’s desperate eyes. “I cannot reward you,” one said. “I cannot give anything belonging to me, of my own free will, nor anything belonging to another—for to do so would be to bind myself within the sacrifices of this stone, as all those who have carried it have done. And that, I must not do. I am the motherfather of this domain. You presented the stone as a gift to me and to the lord of Tepatiliztlan; I accept it as such. Your reward must be gratitude, which is not lost by being given. Now go.”

Cenquiztli did not watch as Jachanel hesitated, bowed, and departed, leaving one alone in the chamber, without even a fan-bearing slave to stir the air. Let the trader suffer his grief and rage without a witness. What mattered was the stone.

One began to whisper the ritual calendar, the endless cycling of numbers and days, without beginning and without end. Its rhythms were the heartbeat of existence, the footsteps of the sun—which once had stood motionless in the sky, burning all the world to ash, until it was propitiated into motion with blood. Cenquiztli could feel the answering resonance from the stone: obsidian within barkcloth, a cocoon within a cocoon, awaiting its chrysalis.

It was afternoon, and the sun was in a good position. Cenquiztli rose and drew aside the curtain of beads that blocked most of the light from one’s small balcony, which overlooked the courtyard where the other high-ranking priests dwelt. The sunlight streamed in, striking the floor and the stone that waited there.

It revealed a striation within the darkness. Rainbow obsidian: Cenquiztli had suspected even before the light confirmed it.

This stone had indeed come to Tepatiliztlan in their day of need. Whatever price it demanded before the end, the lord must pay it. She had no other choice.

Still Cenquiztli did not touch the stone. One’s wooden flesh had no blood to give, but the obsidian would claim other things, if given a chance. The wet season was the season of abundance, of giving, of self-sacrifice. The dry season was the season of scarcity, of hunger, of sacrifices taken from others. One had struggled for many long years before achieving the balance one had now, a balance that freed one from the dangers that came with being xera.

That balance might survive contact with the stone. One might be the single person in this domain who could claim it without paying its price.

Or one might not.

I will not try to cheat the gods. Everything in the world came with a cost, from cycle of day and night, to the fertility of the earth, to victory in the wars that threatened to destroy Tepatiliztlan.

The stone must continue on its journey.

Cenquiztli rang a bell to summon a servant. When the young amantecatl page entered, one said, “Send a message to the House of Flint.”

Of all the amanteca within the House of Flint, only two truly had enough skill to work a large piece of rainbow obsidian—and from the moment she saw the stone on the floor of Cenquiztli’s chamber, Xamania had no intention of allowing Iyaotl to win that honor.

The amanteca were given four days to bring their best pieces before the chief artisan. After studying those, the chief artisan would choose who had the skill to work the stone. The day before the presentation, when Iyaotl left her workroom to fetch water, Xamania slipped in and found the piece her rival had been working on since before the rainbow obsidian arrived: an eccentric flint half as tall as she was, wrought in strange and grotesque branches, with faces chipped into the edges that masterfully evoked the iconography of the gods.

It was almost complete, and finding the right spot took Xamania several breathless moments. She could not shatter the flint; that would be far too obvious. She had to be more subtle. But eventually her clever fingers found an area of thickness, left to support the weight of the branching edges of the flint above. Xamania took out her favorite antler nub and pressed it against the edge, until a shard flaked off. This she snatched up and tucked into her pouch, along with the antler, then replaced the flint where it had been.

Later that afternoon, a scream echoed through the House of Flint. Xamania stayed in her own workroom, imagining for herself the expression on Iyaotl’s stupid monkey face when she went to put the finishing touches on her flint and snapped the entire piece in half.

The next morning, the chief artisan surveyed their works, from the clumsy spear-heads of the apprentices to the flawless ripple-flaked blade Xamania presented. Of course he awarded the rainbow obsidian to her.

The tear-stained Iyaotl did not even attend.

Cenquiztli had performed the divinations of the ritual calendar and recommended the day Six Deer as an auspicious time to begin. That gave Xamania four days to prepare, and twenty-one days in which to do the work, ending on One Yellow. She began by cleansing herself and her workroom both, fasting and abstaining from all contact. She’d worked obsidian before—small pieces, shards and scraps begged from the highland cities—but never something of this size and significance. The motherfather had authority over all the ritual surrounding the stone, but the working of it would be hers alone.

On the morning of Six Deer, as the light poured in through the unshuttered eastern window, Xamania settled onto her mat and unwrapped the stone.

Alone in her workroom, with no eyes watching, she found herself trembling with nerves. She held the stone up to the light and observed the colors along its edges, but even the sun’s power could not penetrate its dark depths. What waited for her there? Hidden flaws, perhaps, that would snap the core when she struck it, just as Iyaotl’s eccentric flint had snapped. Bubbles and imperfections throughout, so that instead of breaking into clean flakes, it would send a shower of useless splinters to the floor. Obsidian was brittle; there would be no using the hard hammer-stones employed on flint and heavy basalt. Antler only, and a great deal of pressure flaking—and if she was both lucky and skilled, the residue of this stone, the pieces chipped free from the core, could be used to make dozens of smaller knives. After years of war and strangled trade, Tepatiliztlan starved of the obsidian supply—starved of its means of speaking with the gods—this could be bounty enough for the entire domain.

If she did not ruin it.

For twenty-one days Xamania worked, consuming only thin atolli flavored with honey after the sun went down, drinking only weak pulque while she worked. She dropped beads of copal incense on the brazier, inhaling the pungent fumes, and prayed to all the necessary gods. Each Day Lord in turn; the patron of the artisan caste; the goddess of sacrifice herself, the Obsidian Butterfly. Each night, when she slept, her dreams were filled with the glassy touch of stone, the pressure of antler against an edge, and each morning she woke to the joy of her work.

Until the sun rose on One Yellow and Xamania held the obsidian up to the window once more. This time she saw its full glory: translucent bands of green and blue, red and gold, the stone flaked so impossibly thin that it seemed hardly to be stone at all.

Xamania would have wept, but tears were not the sacrifice ritual demanded. Instead she took a shard she had saved, a slender point shaded with the colors of the rising sun, and pierced her tongue. Ordinarily she would have caught the blood on bark-paper and burnt it, but this time she let the drops fall, spattering both sides of the blade, down at one end where she had left a neck for hafting. Then, with the copper of her own blood still sharp in her mouth, she took the hilt that had been delivered while she slept, bone inlaid with gold, and bound it onto the blade.

Her work was complete. She had done what no other artisan in Tepatiliztlan had done—might never do. Stone for a blade like this came once in a lifetime, if that. Never again would others speak of Iyaotl and Xamania in the same breath, as the two jewels of the House of Flint; now it would be Xamania alone, the pre-eminent artisan of all the city. The chief artisan was old, too. It might not be long before she was elevated to his place, the first flint-worker to be so honored.

No. Not a flint-worker. A worker of obsidian.

Gathering up her triumph, Xamania opened the door, and went to meet her glory.

Motzaloa gazed out over the great nobles of her realm, gathered in her hall to see the blade presented. Tall ocelotlaca warriors; the slender, monkey-like forms of the amanteca; even those few from the common castes who had risen to great office under Motzaloa’s rule. But the highest of their finery looked cheap, for the wealth of Tepatiliztlan lay in salt, not gold, and the conflicts with Iztlacatun and Ohuiyotlan had beggared their domain. Even Motzaloa was splendid only by comparison.

She needed a great victory. And to win that, she needed the aid of the gods.

“Master of the House of the Dawn,” Xamania said, addressing her words to the stone of the floor on which she lay prostrate. “I bring you the treasure of my hands, crafted with all the skill for which Tepatiliztlan is renowned. May it serve you well.”

On the mat before Motzaloa, the blade waited, wrapped in fine white cotton. All the nobles were watching; she allowed herself to betray no hesitation as she reached out and lifted the bundle. It weighed surprisingly little in her scaled hands, scarcely more than the weight of the cloth itself. As if the blade inside hovered, ready to take wing.

And it would, soon enough. But first, Motzaloa would have to make a choice.

She waved Xamania off, watching only long enough to be sure the chief artisan escorted her away. Cenquiztli had spoken to both the chief artisan and Motzaloa; enough time had passed since a great blade was crafted in Tepatiliztlan that only the motherfather knew the rites that should accompany it. Any person who had poured so much of herself into a great crafting could not be permitted to sully that sacred effort with anything lesser. Tonight the chief artisan would shatter the delicate bones of Xamania’s hands. She would live on royal largesse for the rest of her life, in remembrance of the sacrifice she had made for her work.

Motzaloa spoke into the silence of the chamber. “In seven days,” she said, “at noon on Eight Bird, we shall gather to beg the gods for strength in war. With this priceless blade we shall send a message into the world of spirit, a message that cries out for victory, for the power to drive our enemies before us and bring glory to Tepatiliztlan once more.” Glory—but more importantly trade, the opening of ways, so that they might send out their salt and receive all the things they needed in return. In desperation her priests had prayed, and now she held the answer the gods had sent.

Her nobles shouted in approval and hope. Motzaloa rose and left the chamber, all parting before her. Attendants followed at her heels until she reached the beaded curtain that separated her private quarters from the rest of the palace. Then they fell back and stood sentry. A stronger guard than usual; Iztlacatun and Ohuiyotlan could not have heard yet about the obsidian, but they might have agents in the city who would take action on their own. The attendants guarded their lord as a matter of course, but the blade needed its own protection.

Motzaloa’s hands trembled as she laid the bundle aside.

She could hear Ocachihualli outside, in the small courtyard of their quarters. His shouts rang from the stone walls, wordless, energetic cries. Motzaloa knew even before she went to look that he was practicing, lunging at imaginary enemies with his spear. His scales gleamed gold in the sun, and his quetzal feathers danced in accompaniment. Newly arrived at his full growth, still young and bursting with life.

He thought himself unobserved, and she watched him with pain in her heart. Her heir, her son, her only child. In time she might hope to bear another—perhaps. The aluxob lived short lives with abundant children; for quetzalcoameh it was the opposite. Today, in this sunlit courtyard, Ocachihualli was all she had.

Today, they were both safe. What of tomorrow, though? What of Iztlacatun and Ohuiyotlan; what of war and the threat of conquest? Tomorrow there might be no Tepatiliztlan, except as a subject city ground beneath the heel of their more powerful neighbors. Motzaloa and Ocachihualli might live for years after that, as captives of their conquerors. Brought out on the great ritual days, made to bleed time and again for the victors, a continual sacrifice to please the gods. They would not receive the mercy shown to those who gave themselves willingly, the drugs to numb the pain; for enemy nobles, suffering was part of the ceremony. Her beautiful son would live on in recurrent agony.

The god of the feathered serpents did not ask to be honored with blood. But the god of the feathered serpents was only one among many, and to save her people, Motzaloa needed more.

She watched her son without blinking, not as a mother but as the lord of Tepatiliztlan. She carved out of her heart the love she felt, the pride and fierce attachment, that would make her put this golden moment above the well-being of her city. The star of war was moving into auspicious position, Cenquiztli had told her—and now this blade came, the instrument of a great sacrifice. To save her domain, from her nobles in their shabby finery down to the alux peasants scrabbling in their fields, she must pay with treasure far more valuable than gold.

Against that, her love was nothing.

And so she sacrificed it.

Lying within the soft cotton of its final cocoon, the obsidian felt the heartbeats of all those who waited in the plaza below. People of every caste, noble and commoner alike; residents of the city; outsiders from all the villages of the domain. All those who had heard of the great sacrificial knife and were able to reach Tepatiliztlan in time, packed at the foot of the great pyramid. The stone vibrated with each beat of their hearts, their bodies pulsing like drums, filled with the precious substance that bridged the worlds of flesh and spirit.

Another drum: Ocachihualli’s footsteps, climbing to the heights of the temple. Slow and careful, not only for dignity but for balance; the drink given to him numbed his senses and made movement uncertain.

Only those drums and the whisper of the breeze, scarcely dimming the punishing heat of the noonday sun. All else was silence.

A silence broken by Cenquiztli’s voice, crying out prayers for the people below and the gods above. Then the faint scrape of feathers against stone as Ocachihualli bent himself backward over the rounded top of the stone. Ankle and wrist bells shimmered with soft music as four ocelotlaca held him fast, one at each limb, pinning him against the struggles he did not try to make.

The cotton fell away and the blade rose high in Motzaloa’s hand.

Obsidian Butterfly: that was the name given to the goddess, of whom it was only a fragment. The personification of sacrifice, whose sharp-edged wings cut the veil between the worlds. The gods of fire and earth had sent this piece of her into the world for a purpose. Now its time had come.

It flew as it was made to do, by an artisan’s hands and the cycles of the cosmos, where nothing came without cost. Out of the sunlight, sheathing itself in the body below. Blood surrounded it, hot and holy—and at last, at last, what had once been mere stone became something more.

The axis mundi, the point around which all things revolved. The place where life met death, where the mortal met the divine.

A few quick strokes of its sharp edge cut Ocachihualli’s heart from his chest. Soon his flesh smoked in the sacred flames before the altar, bearing the prayers of the gathered people to the ears of the gods. For victory, for survival, for hope. Ocachihualli’s was only the last of the sacrifices made for that prayer. The knife remembered Konil, and Jachanel, and Xamania, and Motzaloa, who stood atop the pyramid with her eyes burning dry in defiance of tears. Whether of blood or not, whether given willingly or taken by force, the price must be paid.

It was not for the knife to judge. Today it had fulfilled its purpose. Tomorrow, next year, a century from now, it would do the same, until it too was broken, becoming a precious sacrifice.

Stone was patient. Lying atop the altar in its cloak of blood, the obsidian butterfly waited, again.