February 11, 1907

By the time we arrived in the Manchu settlement of Tanbian, the Russian expedition had already left a day earlier.

For the last five days, we have been moving through deep snow and dense primeval forest in the Changbai Mountains, trying to catch up. The superiority of the mechanical horse is becoming clearer with each passing minute.

Look at these magnificent creatures. Observe each steel foot confidently stepping forward, gripping the snow with meter-wide lattice-work snowshoes. Be amazed at the smooth ride as they effortlessly carry five men and eight hundred kilograms of supplies. Marvel at the frictionless joints flexing and bending in complete silence, lubricated by whale oil. Hear the overlapping metal plates slide over each other as the horses leap over dangerous crevasses. Feel the rumbling warmth as you run your hand over the chrome skin, heated by the pumping engine within while feathery snow falls all around you.

I cannot imagine conducting the current expedition using dog sleds. Dogs require sustenance and rest, but mechanical horses do not. Taking turns to rest on horseback while our companions held the reins, we have been moving nonstop.

“Yirin,” I call to our Manchu guide — barely sixteen, hardly more than a boy. “How much further to the spot you spoke of?”

“Maybe as long as it takes to drink a pot of tea, Dr. Nakamatsu,” he replies, brushing his mop of unruly black hair out of his eyes. “Soon, very soon.”

As Yirin knows no Japanese and I no Manchu, we are forced to converse in Chinese.

Hissssss. The horses open the exhaust valves located in their mouths, and white steam ascends into the frigid Manchurian winter air like smoke rising out of the crater on Mount Changbai.

The Imperial Army, which paid for this expedition, has supplied us with ten Type Ten mechanical horses, each costing as much as a small gunboat. These were designed for cold climate operation in anticipation of an inevitable second war with Russia in Manchuria in the future. Part of my mission is to field-test them.

So far, I think they are passing with flying colors.

“We’re here,” Yirin says. “This is where my father and I saw the bear last spring.”

We emerge from the forest into a clearing, in the middle of which lies an enormous heap of bones.

• • • •

I still remember that night, almost four decades earlier, as though it were yesterday.

I woke to the sound of a loud crash. As I sat up and opened my eyes, I did not understand what I was seeing. The eastern wall of our one-room house had disappeared: in its place, the howling wind, made visible in the moonlight by swirling drifts of snow.

“Jokichi, run!” Father called to me.

He stood in front of me, trying to block me from a shadowy figure seen indistinctly through the snow. My mother lay before him, unmoving. As I watched, the shadow came closer, stood up like a man, and loomed over my father.

The shadow growled, a sound that made me shiver. I saw the great, black, furry head, the sharp white teeth — the front ones curiously notched, like a key, the outstretched paws promising a deadly embrace.

I screamed.

My father shouted and rushed forward, his spear aimed at the bear’s heart. But the bear swiped at him with a speed and agility unbelievable in a creature of such size. The spear snapped like a toothpick. A moment later, my father flew through the air like a rag doll, his head already crushed by the bear’s paw.

I forgot how to move. The bear shuffled closer, and the smell of rotting meat and animal sweat was overwhelming. I felt as if I sat at the bottom of a mountain, a mountain of flesh, fur, and death.

I closed my eyes, waiting to die, the bear’s hot breath on my face.

A searing white flash of pain, then nothing.

Later, the rescuers told me twenty-six men, women, and children were killed by the bear that night. I lost a father, a mother, and my right arm.

Today, if you go to the place where the village once stood, tucked into a cove on the western coast of Hokkaido, you will find a stone monument with the names of the victims in the spot where our house used to be.

I have visited once every few years to say a prayer for my dead parents and to make a promise.

The bear was never found.

• • • •

I pace from one end of the skeleton to the other, examining each bone.

The Ussuri bear — Ursus arctos lasiotus — of Northeast Asia is the ancestor of the American grizzly. A fierce and powerful predator, it has no equal in its domain — indeed, it regularly seizes prey from Siberian tigers and even occasionally kills the big cats. On Hokkaido, the native Ainu used to worship the Ussuri bear as a god.

The largest Ussuri bear I have ever laid my eyes on weighed 650 kilograms. Alive, the one before me would have weighed three times as much.

“It is too large to be an Ussuri,” I say to Shiro Ito, our weapons master.

He nods, awed into silence.

Many cultures in Northeast Asia have legends of a race of gigantic bears. The Ainu speak of the god who possesses the mountains. The Manchus and Koreans tell stories of enormous bears that live near the peaks of the Changbai Mountains. The Chinese call the great bears xiongjing, or bear spirit.

In these stories, besides their enormous size, the bears are distinguished by their ferocity and the possession of near-magical abilities of healing and regeneration. Most fantastic of all, they are supposed to be highly intelligent and able to take on the form of a man when desired.

I do not put much credit in the superstitious elements of these tales. All bears occasionally stand on their hind legs, and it is easy to see how frightened peasants could mistake such a posture for a magical transformation.

But other aspects of the legends have the ring of truth. The Chinese put much stock in the medicinal qualities of bear gallbladder, and a fast-healing bear may well teach something of use to a man of science. The Army is certainly interested in such knowledge as well as the possibility of taming and training such intelligent bears for military use. Like the mechanical horses, bear-soldiers might prove to be the decisive factor for victory in the harsh conditions of remote Manchuria.

Such are the official goals of our expedition.

I run the fingers of my right hand, the one made of metal, over the large ribs gently. The prosthetic is outsized, thicker and longer than a real arm, dangling past my knees. The actuators hiss as the chrome fingers flex and bend, tapping against the bones like delicate hammers striking against the keys of an oversized xylophone. The sound is muffled, indicating that the skeleton is not very old, likely picked clean by scavengers.

The position of the skeleton is curious. The body has been arranged so that the bear lies on its back, face pointing up and the hind limbs kept straight, with the forelimbs folded across the chest, like a man having gone to sleep.

But it is the bear’s teeth that are of most interest to me; the lone front tooth remaining in the jaw is curiously notched, like a key. I lean down and stare at it, trying to match it to a child’s memory.

I take out a compass and verify that the bear’s head is pointed directly south.

This is not how wild animals die.

“My father and I were tracking a herd of wapiti last spring when we followed a doe into this clearing,” Yirin offers.

“Did you move the skeleton?”

“We took some finger bones and teeth as proof, but nothing else.”

“No one in the village had ever seen it before?”

He shakes his head.

“You are certain that there are no villages closer to here than Tanbian?”

“I’m certain.”

I dismiss him and continue to examine the skeleton. He probably is telling the truth. If other villagers had seen the bear, they would have taken more of the bones, which can be quite lucrative for bone carvings or as ingredients for traditional Chinese medicine. It would have been a hard secret to keep. Indeed, Yirin and his father had sold the teeth they took in Mukden, which was how we heard about the discovery in the first place.

I had seen one of those notched teeth and immediately pushed for the expedition.

So I can safely rule out human intervention as the cause of the skeleton’s strange posture.

I gaze into the hollow eyes of the bear’s empty skull, almost as large as my torso. I try to match it to the shadow in my memory.

Could the legends be true? Could this skull once have housed a deadly mind as intelligent as a man’s?

I pick up one of the arm bones.

Even after all these years, I can still feel my phantom right arm, the arm that the bear took away from me on that night.

As I lift the phantom arm, the impulses in my severed nerves charge tiny capacitors, which amplify the signals via resonator circuits. The signals, in turn, drive electromagnets that are attached to governor gears, altering the power the steam engine sends to the intricate gear train until my piston-driven steel arm has assumed the posture of my phantom one.

I will my phantom fingers to squeeze, and my metal fingers follow suit. I will my phantom fingers to squeeze harder, and as hundreds of gears grind, the pistons of my hand are brought to their full power, and suddenly, the bone in my hand shatters into a thousand pieces.

The grin in my memory matches the grin in the skull, perfectly.

This is the bear that attacked my family decades ago.

I will not be able to keep my promise to my family after all. The bear is already dead.

“Dr. Nakamatsu,” Yirin calls from the edge of the clearing. “You must come see this.”

I walk over. Yirin is pointing to a dead man’s hand sticking out of the snow.

• • • •

“The Russians did beat us after all.” Daiki Hayashi is our mechanic.

“Not that it matters,” says Ginnosuke Abe, the medic, “by the look of things.”

We dig through the snow. Altogether, we find the remains of six bodies.

One is remarkably complete, missing only a hand. The others are less intact. Of the last one, only a stump of a foot is left, the oozing blood frozen into tiny icicles.

Ginnosuke bends down and warms the frozen blood with his hand, sniffs.

“Less than two days old,” he declares. He examines the bite marks and the way the bodies have been flattened. “The bear that did this isn’t quite as large as the skeleton. But still, it must weigh nearly a thousand kilograms.”

I bend down to examine the bite marks myself. The cold has preserved the wounds in remarkable detail. I can even see the lines made by the individual teeth: like scraping marks left by a key.

“It will be back tonight,” Shiro says.

“Why?” asks Daiki.

“The bear is still hungry,” I reply. “It’s been using the snow as an icebox to keep the food fresh. Let’s set up camp and perimeter defenses.”

• • • •

Daiki has arranged the ten mechanical horses in a circle around the campfire: their hindquarters facing us, their heads facing out.

In the flickering firelight, they stand still, without the fidgeting and snickering that real horses would have engaged in. Now that their boilers are set to low heat, their shells have cooled and the falling snow soon covers them, turning them into snow sculptures.

But wisps of white steam continue to escape from their chrome nostrils, melting the snow over their faces and rising into the crisp night air. Their eyes glow red with the heat deep inside.

I brush the snow off the horses and open each belly, taking out the rolls of paper covered with holes arranged in neat patterns and replacing them with new ones. The old rolls were for marching, the new ones for defense.

“What do the holes do?” Yirin asks.

“Have you ever seen a player piano?” I ask.

Yirin nods. “When I went to Mukden with my father to sell the bear teeth.”

“It’s the same principle. The holes are instructions like the scores for the pianos. It’s called Lovelace code. If anything approaches from outside the camp, with a light tap, the man keeping watch can make the horses come to life without a rider. They will then move in accordance with the directions on the paper to fight the intruder.”

Yirin touches the metal skin of the horse gingerly. I see he has gained a new respect for the horses. They are more than mere beasts of burden.

Shiro shoots a half dozen hares for our dinner. Ginnosuke sets them to roasting over the fire. We sit in a circle sipping from cups filled with tea made with melted snow water, waiting.

“They’re ready,” Shiro says.

I reach into the flames with my metal hand, pull out the meat, and pass the pieces around the fire.

“Dr. Nakamatsu,” Yirin asks, as he accepts his portion. “Is it strange to have a metal hand?”

“I’m used to it.”

He continues to stare at my hand, and I smile, indicating that he may touch it.

Watching him approach my hand and arm the way he approached the mechanical horses gives me an odd feeling, as though I am looking at myself through the eyes of a stranger.

• • • •

The bear attack had occurred a few years after the Emperor took his power from the Shogun, the beginning of the Meiji Restoration.

My family was not from Hokkaido. Samurai loyal to the Shogun, including my father, had come to Hokkaido to set up a separate country.

“The Emperor wishes for us to use the foreigners’ machines and to learn to think like them,” my father said. “He wants to make Japan no longer Japan. We must chart a separate course.”

I nodded, secure in my father’s wisdom.

There was much that had to be done: chopping down trees to build houses and to clear out fields for the crops; burning charcoal for the weaponsmiths’ forges to fashion the best samurai swords; hunting for bears and wolves to make the land secure so that we could sleep at night.

I still have fond memories from that time, following my father around with a toy sword, stabbing at imaginary bears.

But the Emperor did not leave my father and his companions alone. The Emperor’s soldiers, masses of peasants armed with European guns, came to Hokkaido, surrounded the samurai, and slaughtered most of them in a battle with little honor. My father had been lucky to escape, hoping to hide with my mother and me in an obscure village.

But the bear had found him.

To show compassion to his former enemies, the Emperor’s men took me, an orphan, back to Tokyo.

At first I did not wish to study the things my teachers wanted to teach me. I sat in silence and held onto my empty sleeve with my left hand.

“Japan must remain Japan,” I said stubbornly, repeating the words of my father.

“Japan must change to remain Japan,” my teachers said, “or else the foreigners with their gunboats will turn us into meat lying upon a butcher block.”

A child could resist only so long. Eventually, I was given a proper and modern education and fitted with a series of new arms.

At first, my arm was carved out of wood, like the arms that had been given to cripples for hundreds of years. It could not do much save for filling out the right sleeves of my robes.

Then, as the country humbly learned the secret of steam and machinery from the Western powers, my arm also began to change.

When I was ten, I was given a clockwork arm, full of springs and gears and a key that I could wind with my left hand so that the iron fingers of my right hand could open and close. I studied mathematics and works of science translated from English and French while mills and workshops sprang up around me like mushrooms after rain.

When I was twenty, I was given an arm driven by steam. It was bulky and heavy and the boiler sometimes burned me. I had to keep it fed with water and coal, but it was also strong and hardy. I entertained my friends with feats of strength and helped them carry their heavy luggage as we went to the harbor to get on ships bound for Europe and America, where we were to study the latest knowledge of Western science. As I left for America, I waved to the new gunboats of the Imperial Navy in the harbor, modeled on British ships.

When I was thirty, I returned to Japan as a doctor of biology. My arm was now much lighter and stronger, and it was powered by electricity stored in a battery. Just by pressing a few buttons I could make it flex and bend, and by twisting a few knobs I could make the fingers open and close and hold any position. And I remember waving it in the air as everyone in the city celebrated Japan’s defeat of China and the conquest of Taiwan and Korea. We were on the rise, like a blast of steam from the exhaust at the top of a factory.

When I was forty, I finally received my present arm. It was the first arm that obeyed my will directly, its wires and components embedded into my nerves and flesh, its gears and levers driven by a steam turbine. As I and the others rejoiced in disbelief at our victory over Russia in Manchuria — the first victory by an Asian power over a European one for as long as people could remember — I felt an electrical surge from my joyfully pumping heart to the tips of my steel fingers.

Just as my country had transformed itself from a feudal backwater into a world power under the Bright Reign of the Meiji Emperor, finally, this foreign thing, this piece of machinery, had been transformed into a part of me under the light of science.

But through it all, I never forgot the bear.

In my years in America, I traveled widely, studying the habits of grizzlies and learning their lore. And after my return, I crisscrossed Hokkaido for many years without ever finding any signs of the bear that attacked my family. Yet, I did not believe it had died. I could feel it still out there in the world, mocking me.

And now it seems that the bear had left his home to wander the world just as I did, and the bear had multiplied.

• • • •

“That’s enough,” I tell Yirin and pull my arm away from him. “It’s late. Time for rest.”

Shiro agrees to take the first watch while the rest of us sleep.

Exhaustion from the past five days finally catches up to me, and I welcome the oblivious embrace of sleep almost immediately.

• • • •

I wake up to a nightmare.

For a moment, I do not understand what I am seeing. Under the moonlight, bits of torn paper are everywhere, swirling with drifts of snow in the howling wind.

Then I notice that nine of the mechanical horses have the flaps under their bellies hanging open, the space inside, where the scrolls of code should be, is empty.

A dark shadow is crouched next to the last horse.

I am frozen. I have forgotten how to move or speak.

The shadow rises from next to the horse. It is a bear standing on its hind legs: a big bear, as big as any Ussuri I have ever seen.

A figure lies unmoving next to the bear: Shiro. The bear must have killed him first as he was the watchman.

An electrical tingling in my mechanical arm rouses me from my stupor. “Daiki!” I call out. “Ginnosuke! Yirin!”

Daiki rises from next to me. He fumbles for his gun.

In a second the bear is next to me. He growls, and I shiver.

The bear swipes and Daiki is hurtling through the air, like a flying fish leaping out of the water, casting a graceful arc across the falling snow, through the cold Manchurian moonlight.

The bear continues to grab onto everything in camp and tosses it out of the way. Boxes and bundles — a few that might have been Ginnosuke and Yirin in sleeping bags — are flung afar like broken toys. The bear is like a typhoon, an unstoppable force of nature.

I roll away from the chaos and find myself next to the last horse, the one horse that still has its fighting instructions.

I reach up and tap the switch next to the horse’s neck.

And then I am flying through the air too, and as I land in the soft snow, I feel a searing pain in my thighs. I try to stand up but can no longer make my legs obey.

The bear growls and lumbers through the snow towards me. I smell the rotten stench of its breath and sweat. The bear’s eyes are inches from mine. There is nowhere for me to run, even if I could move.

The bear opens its mouth and growls again, lunging towards me. Without thinking, my right arm shoots out and my steel fist connects with the great snout. The bear backs off in pain, surprised by the power in my arm. But it shakes the blood from its nose and is back in an instant, and swipes at me.

We wrestle and I grab the bear’s arm with my metal fingers. I squeeze, trying to crush its bones. But the bear seems to feel nothing as it leans down, slowly pinning my mechanical arm to the ground with its weight.

I look towards my steel fingers and see that I am holding onto a thick branch. The bear has fooled me. It had swiped at me with a club like a false arm.

I close my eyes. I have been outwitted by a bear, a bear that does not behave as one. I will die as my father before me. The pressure on my chest is crushing and I cannot breathe.

Suddenly, the bear roars in pain and the weight on me is gone.

I open my eyes and see that the mechanical horse has finally come alive. It rears up its forelegs and stomps them on the hard-packed snow.

The bear limps a bit, and I can see a swelling lump on its back where it was kicked. It stands up warily to face this new menace, this mechanical foe.

Animal and machine rush at each other, clashing in the snow. The sound of claw scraping against metal grates at my ears, accompanied by the labored breath of the bear and the straining whine from the horse’s boilers. The two pit their strengths against each other: one an ancient nightmare, the other a modern wonder.

Gradually, the horse appears to gain the upper hand: it pushes the bear ever so slowly backwards. The bear strains, tries to hold its position, but its legs tremble with the effort. It stumbles back a few steps and with a roar halts the retreat momentarily, but in a few seconds stumbles back again.

I smile. Muscle, after all, cannot match piston.

But my smile freezes as I realize that the bear is shifting direction, lurching backwards towards me. The wily beast, knowing that I am paralyzed, is pretending to lose. Since I cannot move, I will be crushed either by the bear’s paws or the horse’s hoofs as the pair step over me.

The horse pushes forward relentlessly, oblivious to the scheme. Animal intelligence has found a weakness in my programming.

A gunshot cracks.

I see that Daiki is sitting up in the snow, his gun cradled in his lap as he aims at the bear’s head for a second shot.

The bear, realizing its weak position, roars and shoves the horse back, ducks and rolls out of the way, surprisingly agile. The horse stumbles, loses balance, and crashes to the snow. The bear, now ten meters away, gets back up on its feet and begins to run.

Another gunshot, another miss.

The bear disappears into the swirling snow and dark night.

The mechanical horse regains its feet. Now that the threat is no longer nearby, it stops moving, though its red eyes continue to glow in the darkness, like night lanterns at a harbor.

Daiki and I stare at each other, unable to believe our luck.

Suddenly, the horse comes back to life and rears up on its hind legs.

“It’s us! Don’t shoot!” someone shouts.

Ginnosuke stumbles back into camp, his leg wounded. Behind him comes Yirin, who is also limping, a hand on his back. Their faces are white, the look of haunted survivors.

The bear had indeed thrown them out of the camp in its frenzy. They are lucky to be alive.

All four of us look towards the unmoving body of Shiro, not nearly as lucky.

• • • •

“To stay here is madness,” Ginnosuke says. “All of our horses, but one, have lost the ability to fight. Our best warrior is dead. Your legs are broken and the rest of us are injured. The only course is to admit defeat and retreat.”

Ginnosuke speaks sense, but I cannot help being who I am. If I cannot have my vengeance against the bear, I must have it against the bear’s children. I cannot forget that night so many decades ago. Our obsessions are a part of us, like our scars and phantom limbs.

“We cannot return empty-handed,” I say. “The bear who attacked us last night was juvenile. We have not yet seen the adult who killed the Russian team. We must capture both.”

Ginnosuke, Daiki, and Yirin look at me as though I am mad. Perhaps I am, a little.

• • • •

I sit in the middle of the camp. Snow has covered the shredded tents and our scattered boxes of supplies, turning them into misshapen mounds of snow. Now and again, I brush the snow off of myself.

Before they left, Ginnosuke and Daiki took off a pair of legs from one of the horses to fashion splints for me. At least the pain is now bearable, even if I cannot move.

My companions have taken the other horses and left me behind. The giant bear skeleton alone keeps me company.

Slowly, oh so slowly, the light fades, and evening falls.

A roar fills the woods, and winter birds, roused from their sleep, burst into the sky in panic.

The second roar is much closer.

I pull my coat tighter around me. The electrical tingling shimmies through my arm again. I open my metal fingers and look at the tiny glass vial held inside, filled with a clear liquid that refuses to freeze in the sub-zero cold.

This is my secret weapon: There is enough neuropoison in that vial to paralyze a great whale. We brought it to tranquilize any bears we catch.

The bear roars again, and I look towards the edge of the clearing. The trees shake and tremble as though they are in the middle of a storm.

The ground shakes, and a large shadow steps into the clearing, a shadow that is a reflection of the one I have seen a thousand times in my dreams.

The great bear rears up on its hind legs and opens its mouth. I see the notches in its teeth glinting in the moonlight.

Then it plunges back to the ground and snow explodes around it like icebergs calving. Its demon eyes are bright in the moonlight.

“You’re from Hokkaido,” I say.

The bear cocks its ear, as though listening. Then it grins. It growls lightly in answer, like a chuckle.

“I have been looking for your father,” I say.

It stares at me for a while, then nods and lumbers forward, slowly at first, and then gradually picking up speed.

I curl my hand and lay my arm down in the snow, an obvious target. After all these years of searching and plotting, my plan has come to this: I must allow it to take my arm into its mouth, where I can crush the vial and release the toxin. I am both the bait and the bear trap.

The bear stops a meter away from me, breathing hard. We stare into each other’s eyes. Who is the hunter and who is the prey?

The bear looks down at my mechanical arm and shakes its head. I tense. Has it divined my plan?

Quicker than I can believe is possible, it pounces on my arm and the weight of its massive forepaws immobilizes my artificial limb. I am pulled to the ground and groan as my broken legs are jostled. The bear grins, contemptuous.

But my arm has tricks that the bear does not know. Unlike an arm of flesh, my prosthetic arm is capable of continuously turning in its socket in the same direction like a wheel. As I turn my arm one revolution after another, I move the bear’s weight off of it like a slab rolling off of a log.

The bear, surprised, is too late to react as I grab onto its forepaw and squeeze with every bit of strength my gears and levers can muster. It howls, an inhuman sound. The pain immobilizes it. I continue to increase the pressure, a force that no flesh can compete with. I hear the bones in the bear’s arm crack and shatter.

A momentary lull in the swirling snow allows the moonlight to glow brighter, and shadows stir behind the bear. Three mechanical horses emerge from the snow. Their riders hold guns aimed at the great bear.

I grin back at the bear and let up the pressure for a moment. “I have you now.”

The bear bites down hard to stop the howling. It turns its head and sees the riders. Behind them, the rest of the horses appear, tied together with chains so that they form a moving wall of iron. Though the horses can no longer fight, they still have their riding instructions and will follow a rein. No matter how strong the bear is, it will not be able to break that wall.

The bear roars, a sound of surprise and despair.

The real trap has sprung. My companions have been hiding behind a nearby hill. They have cut off the bear’s route of retreat. The bear will die today in this clearing, even if I die with it.

I see Daiki, Ginnosuke, and Yirin raise their guns. I begin to laugh. Finally, after all these years, my nightmare is about to end. I squeeze my mechanical hand even harder, wishing to literally rip the bear’s arm off.

The smallest of the three riders — it must be Yirin — drops his aim, grabs his gun like a club and swings it at the heads of the other two men before him. Without any sound, the two of them fall from their horses. Yirin jumps off his horse and lets the reins dangle.

I do not understand what I am seeing.

Now bereft of guidance from their riders, all the horses stop moving.

Yirin alone approaches the bear and me. He points his gun at me. “Stop.”

I let the bear’s arm go.

“Father, please excuse my tardiness,” Yirin says in perfect Japanese, and bows to the bear.

• • • •

I watch, mesmerized, as Yirin transforms into the bear who broke my legs last night, and then back to Yirin again. I watch, wonder filling my heart, as the great bear transforms into an older version of Yirin, a tall and broad-shouldered giant of a man with a head of hair and a beard as bushy as a hedgehog. He cradles his bloody, broken arm as we talk.

“My name is Airin.” His voice is deep and resonant, sorrowful but calm.

I look into the man’s eyes. “Your father killed my family, almost forty years ago.”

“As yours did mine.”

I shake my head, not understanding.

“Since time immemorial, our clan of bear-men have lived in the snowy forests of Hokkaido, away from the presence of men.

“Then, gradually, more and more men from the southern islands came, and began to cut down the ancient trees of the forest, to burn down our home so that they could have flat fields on which to plant their crops.

“And they hunted us, killed us as we slumbered in winter.”

I remember how my father’s people had to make homes for themselves in the wilderness of Hokkaido, how they had to tame a land that was uncultivated, how they had to kill the bears to make the village safe. The bears had to make way for people.

“A blood debt demands payment in blood,” Airin says. “My father went to your village to avenge the deaths of his brothers.”

I feel my mechanical arm tingle, the phantom limb in pain.

“But more men soon followed those he killed, and eventually we had to flee Hokkaido altogether and come to this new land, where the smell of men is faint. But blood always calls for more blood.”

I look at Airin. Who between us is the prey and who the hunter?

“What do you want?” I ask.

“To change.”

• • • •

I watch as Daiki cuts my arm away from me. The pain is excruciating. Losing my arm a second time is even worse than the first.

Ginnosuke helps by separating the nerves and blood vessels that have grown into the spaces between the wires and gears with a scalpel. He cauterizes the wounds with a heated iron. I know that the cauterization process, though necessary to save my life, will make it impossible to receive a new arm.

“Drink,” Ginnosuke says, and feeds me a burning liquor that will bring me sleep.

You have not left us alone. I hear the words of Airin through a haze. Every year, men cut down more trees, burn more grass, open up more fields. You can do it so much more efficiently now with the aid of your machines, powered by belching mechanical engines.

Our magic has always come from the earth, the raw soil of endless life. But men have torn open the earth to plunder the energy locked away in death, for coal and oil, and for lumber and stone with which to build. They have bound Manchuria in iron chains laid across her so that steam-powered monsters could huff and puff over the land and haul the goods to the sea.

Drowsy, I watch as Ginnosuke and Daiki work together to attach my arm to Airin. An arm for an arm, the oldest law of the world. The amputation of his broken, useless arm is every bit as brutal as a scene from a butcher shop, with bone saws and gushing blood and gore-soaked tourniquets. But Airin endures it all without making any sound.

Yirin watches anxiously.

“Do not make a mistake,” he says. He makes his voice menacing but it is hardly necessary. Ginnosuke and Daiki remember well what he had done on the night he killed Shiro.

Daiki has reinforced and thickened the mechanical arm with components from the horse legs to fit Airin’s size. As Daiki clamps the mechanical arm to Airin’s stump, and Ginnosuke begins the process of suturing Airin’s nerves and blood vessels to the wires, Airin hisses but does not otherwise make any sound. He bites down on his lower lip until blood oozes from his mouth.

We have run out of places to hide. We can feel our old magic seeping away as the land loses its life, its energy. It is the same as how it was in Hokkaido. There will be a time when we will want to do nothing but to sleep, even knowing that in slumber men will slaughter us.

If we cannot fight your machines, we must learn to adopt them: your iron horses, your iron arms. The machines have given you power, and perhaps they will give us power, too.

They used the teeth of their father to lure us here, I think. They’ve learned to exploit the energy locked away in death, too.

I watch as the bear-man and the mechanical arm become one. Even with his powers of healing, it will take some time before he learns how to wield this new arm, how to stop feeling the revolting alienness of metal laid over a phantom. But by then he will have felt the power, understood the beauty of cold, invincible steel.

Starting tomorrow, the bears want me to teach them the art of programming the mechanical horses, so that they can be taught to fight. They want Daiki to instruct them in the art of horse maintenance. They want to learn from Ginnosuke how to meld flesh and metal. When they have learned enough, they will let us go.

As I drift towards sleep, I imagine an army of bear-men augmented with mechanical limbs and mechanical horses making a stand against the ever-encroaching tide of men. I imagine a race losing an old magic as they learn to live with a new one. I do not know if I should feel pity or terror.

Airin’s flesh and the metal of the arm will fuse into one, as tangled as blood debts, as beautiful and strange as the great metropolis of Tokyo, where ancient rice-paper lanterns now glow with the burning heat of tiny lightnings, voltaic arcs created by electricity leaping across leads.

I close my eyes and give in to sleep, though my phantom arm throbs with an old magic that refuses to die.