Until the shock of the collapse woke it, the Night Digger had been deep in hibernation, hoarding what little mana it had.
But now, it was starving.
The Mirror Mantis twisted its body in midair and sprang.
Its scythe bit not into its original target but into the thick flesh of the Night Digger.
The Digger let out a roar full of pain and tried to seize the intruder with a huge claw that split the earth as it surged up.
Ren froze where he stood.
Barely two steps away, two nightmarish monsters wove metal and earth together in a lethal dance.
The mantis's shattered carapace burst with ominous flashes in the darkness, and the Digger strained to drag its prey down into the abyss.
Then a small hole, all but swallowed by the darkness on his right, caught his eye.
It was the entrance to an old tunnel, worn smooth by the years.
There was no room for choice.
The fight would be settled soon.
Ren curled his whole body small and crawled into the hole.
Behind him the battle was rushing toward its peak.
The mantis's metallic scream burst out tangled together with the Digger's roar.
A horrible rupturing sound followed, and then...... silence.
Ren could not move for a long while at the edge of the hole, and then at last he dragged himself deeper in.
The sound of his own ragged breathing echoed through the tunnel.
It was so loud that he feared the victorious monster would notice.
'I'm alive......!'
He repeated it as though he could not believe it.
The mushrooms parasitizing his hair spat out a faint light and became the only lantern in the pitch-black darkness.
By that light he could barely make out his own trembling fingertips, and nothing more.
***
'Please let the Digger have won...... please let the Digger have won.......'
Ren muttered as he crawled as fast as he could.
The Night Digger valued its territory and moved slowly.
If it had won, it would spend time eating its kill before it set out in pursuit.
But if the mantis had won.......
The cry of victory that followed soon after froze his blood.
It was not the low, deep roar he had prayed for, but a sharp, horrible shriek of delight.
'No, no, no.......'
While the mushrooms sprouting in his hair faintly lit the way, a fork in the path appeared before him.
The left tunnel had been dug out roughly and unevenly.
It was plainly a burrow bored by some Beast.
But the right one.......
Ren stopped, panting.
The walls were too smooth, too perfect.
Exactly as his father had described them in his story.
"It was as though someone had melted the stone itself. A tunnel of the ancients. A legacy from the days when humans lived here and shaped rock with magic."
A damp, horrible sound came from behind him.
It was the sound of flesh being torn away.
The mantis was at its meal.
But there was no chance one meal would satisfy it.
Soon it would recover its strength and set out hunting again.
In the end, Ren threw himself into the ancient tunnel.
Inside it was far wider.
When the light from the mushrooms on his head revealed the walls, unfamiliar markings came into view.
They were plainly no natural traces.
He could not understand them, but this was without question the road his father had spoken of.
The tunnel seemed to stretch endlessly into the darkness.
Ren ran, driven on by terror and adrenaline.
The time felt like hours, his legs wobbled, and his breath rose into his throat.
In the end he stopped and leaned against the smooth wall of the ancient tunnel.
Remembering how his father had often said, "Berries restore your strength and clear your head," he tossed a few of the ones he had into his mouth.
For a moment he considered lighting a torch with the flint, but then he realized he had not brought any fuel.
Fortunately the mushrooms on his head were still giving off a soft glow.
With his mind a little steadier, he began to analyze the situation again.
By his father's map, he should have found the exit by now.
'Did I take a wrong turn? Or did I pick the wrong tunnel?'
The mushrooms parasitizing his hair gave off a faint light even in total darkness.
They lit only a few meters ahead, but that was better than a torch.
And had they not saved his life, besides?
The Spore he had cursed without pause ever since the summoning was now......
"You're useful, at least." he murmured quietly to the fused Spore, fiddling with the mushrooms on his head.
"Even if it's only as a substitute for a lamp."
He sank down onto the floor.
His legs trembled, as though they had finally been set free.
The water in the canteen was lukewarm, but sweeter than it had ever been.
As he caught his breath and looked at the wall, the mysterious symbols seemed to respond faintly to the light spilling from the mushrooms.
As though alive, they squirmed secretly within the glow.
"I suppose I should thank you for the toads too?"
Ren smiled bitterly, aware that he was talking to the most insignificant creature alive.
"Of course it was pure luck, and you probably didn't even know what you were doing......."
In that moment, an echo rang out from far off.
The metallic grinding of something scraping stone.
And a starving cry that turned the tips of his ears cold.
The mantis had finished its meal.
This time there was no other Digger to turn its attention aside.
He was completely alone.
It was coming for him.
'No...... no, no!'
As the approaching sound seeped into his very bones, Ren shot to his feet.
The mushrooms above his head spat out an eerie yellow light.
There was no time even to wonder why the light had changed.
Ahead lay darkness without end, like a throat gaping black.
There was no side passage to slip through, no shadow to hide in.
Only the smooth ancient stone walls, and the unfamiliar symbols rising and wavering in the mushroom light.
This whole tunnel felt like a trap closing around him.
The sound of a scythe scraping stone, the dull ringing of broken carapace knocking against itself.
The sound bored closer and closer.
The mantis did not even need to run.
It came one step at a time, at an even, merciless pace.
But that very steadiness was the cruelest thing of all.
The Digger's meat had breathed new energy into its body.
Its split exoskeleton creaked like a cursed bell, and that sound foretold death in the darkness.
Ren ran.
The ancient stone slabs rang coldly beneath his feet.
The air sank heavy and pressed down on his lungs.
His breath, bursting out without pause, tangled with the grinding of the scythe behind him until they became one single mass of noise.
SCRAPE...... SCRAPE...... SCRAPE.......
The tunnel seemed to be narrowing little by little.
The yellow mushroom light warped the walls and made grotesque shadows, and the ancient symbols wavered over them as though dancing.
Light swept past.
The mantis's scythe flashed as it split the darkness.
Now, by that light alone, he could clearly see the sickly gleaming compound eyes and the horrible shape of the fractured carapace.
The fact that it was wounded meant nothing.
Even the fact that it had been driven out of its territory did not matter.
The mantis was a Bronze-grade demon beast, and Ren was...... only a child with the most insignificant Weakest Beast in the world.
"No...... please......."
Ren dropped to his knees, swallowing a scream.
His breathing came so hard it seemed about to break, and his awareness wavered.
In that moment, he saw it.
Through the gap in the ceiling from which the ancient fungal spores had come drifting down, a faint light was flowing in along with air from outside.
A hole just large enough for one child to squeeze through.
It gleamed like a promise of salvation.
Ren forced his shaking legs to stand.
An unidentified yellow mycelium had begun to burrow into his body, but this was no time to care about that.
His Spore, 'the weakest Beast in the world,' pulsed with light.
As though...... it were fighting for its life.
Every movement was agony.
The instant his knees began to buckle, he groped at the edge of the hole with his fingers and pushed himself up.
As he crawled out of the tunnel, the light blinded him for a moment.
This was not the outside.
The place he had come out into was a small natural cave.
Its walls were covered all over in glowing crystals that dyed everything a mysterious, cool blue.
But he had no time to admire the cave's beauty, for the invading mycelium kept spreading and devouring his life force.
"Please...... I don't want to die here......."
Ren whispered as he felt his vision blurring.
His Spore fought bravely.
The mushrooms blooming in his hair built a wall of defense against the yellow infection, but the battle was going badly.
Ren felt his awareness dim and his body grow colder by the second.
Just then, he saw a medicinal herb growing at the center of the cave, holding the light of the crystals within it.
It called to mind the very herb his father had spoken of.
'That herb......! The one that helped Mother.......'
Ren muttered as he crawled toward the plant, dragging the yellow mycelium spreading through his whole body with him.
As the edges of his vision began to be eaten away by darkness, his fingers touched the glowing stem.
Ren pulled up the glowing herb with trembling hands.
The yellow mycelium was still spreading through his whole body, but something deeper than awareness was whispering that this was important.
This plant.......
Twelve years ago, his father had found something like it in a different tunnel.
It was the 'miracle herb' that had let his mother bear a child.
But this one was different.
Where the plant his father had found had been hard and sturdy, this one gave off a delicate, ethereal air.
If this one was the 'female,' then the one his father had found was the 'male.'
In the despair of the fungus drawing out the last of his strength, Ren brought the plant to his lips.
The taste was like liquid light, or like the sensation of recalling a forgotten dream.
And then he felt something.
This herb was resonating with something that already existed inside his body.
A sleeping gene inherited from his mother.
It was a sensation like an echo made by the other half of the herb that had miraculously brought him into being.
The ancient herb, divided between separate tunnels for long years, had at last rejoined in full inside his body.
The effect was immediate.
Pure white light burst out from his skin.
It was so intense that the yellow mycelium shrank back, withered like ash, and fell away.
His Spore, the creature they all called useless, began to pulse in a new rhythm.
Perfectly synchronized with the energy now flowing through his veins.
To anyone looking, the Spore would have appeared exactly as it had before.
Small, and plainly weak.
But Ren could feel that something inside him had fundamentally changed.
As though it had evolved into an entirely new variant that no one had ever seen.
He was now a being who had miraculously completed an ancient secret art.
That secret art required three special ingredients: the male plant, the female plant, and a special host born carrying the efficacy of one of the two plants.
The most important part of the secret art was the existence of Ren himself.
The mushrooms in his hair returned to their usual color, giving the impression that nothing at all had happened.
But deep in his being, a sleeping power had just awoken.
A power that would change everything.