Mercenary Black Mamba

He stopped keeping track of the date after his biological clock passed 15 days. The longest cave in the world was the Mammoth Cave in Kentucky state. Its length alone was discovered to be 563 kilometers. The damned cave, however, was longer than the Mammoth Cave.

In Latin, calendar meant an "interesting record." It seemed as though the ancient people had been interested in the changes of day and night, the four seasons, the sun, and the moon. There had to be a change for time to have meaning.

The underground world was a dead world. There were no sun, moon, rain, wind, or changes in temperature. There was only enclosed darkness and heavy silence. He didn't know whether he was alive or dead. There was no meaning to date or time. A world on pause—that was the cave.

There was an Arabic story of a man who was lured by the mirages while driving his caravan and was trapped inside a secluded castle in the desert. The man finally returned home 100 years later after finding the castle's exit. A white-haired grandma spoke of his return, "Father, you look the same even though 70 years have passed." The moment the healthy man heard those words, he aged rapidly. The man, who experienced hair loss and was full of wrinkles, collapsed and died.

The question as to whether the man would have lived peacefully without knowing the passage of time was an unnecessary one. The story was about how perception had preceded reality. If one was made to hold a wooden stick and was hypnotized and made to think that the wooden stick was a hot piece of coal, they were bound to get burned.

In the past, he used to jump up and down angrily at the unfairness of the world, but he was now an adult who had to take responsibility for the consequences of his actions. It was a bleak situation, and he was hungry and exhausted. He'd die the moment despair won. There was no miracle. The determination that came with "it's possible" or "I can do it" was the key to his problems.

He forgot about the passage of time. When he grew hungry, he filled himself up with the dinosaur's meat, and when he grew tired, he laid back against the cold rock floor. The horizontal cave, where heat from the surface couldn't reach, always maintained a temperature around 15 degrees Celsius.

The dinosaur's meat, which remained surprisingly fresh for a long time, began to spoil. Black Mamba stared down at the smelly Boss-saurus' stomach.

"I suppose it's my last feast!"

He'd have to light his eyes on fire to look for insects after eating this meal worth 10 kilograms or so. A Paranthropus' body needed a lot of energy because of their active metabolism. It was the same concept as a car with high horsepower consuming a lot of fuel.

Black Mamba ate up the remaining meat while he prayed. Thinking of his future survival was a luxury. The fact that he was still alive was more important. 200 kilograms of meat disappeared, leaving nothing but the seal-like creature's hide. That was his last portion.

The meat was tasteless and slightly spoiled, but even that disappeared. The cave ecosystem was weak. Not many creatures could adapt and survive the absolute darkness. Bats would live in caves with entrances leading outside, but there were no living creatures aside from the troglofauna.

There were only springtails, grylloblattodea, kurasawatrechus, blind burying beetles, and blind rolling beetles at best. There were very few, and they were all white and small.

Boom—

He activated his dimensional sight. Three to four springtails were detected on his radar.

Woosh—

A variation of the grand sweeping flow spread out. His palm swept across the floor like lightning, catching five springtails. The ohgeumgong with 1,000 years of history was reduced to a mere technique for catching bugs.

The creatures in the cave weren't only small but also lacked nutrients. It was barely enough to satisfy his hunger. The few days he had managed to catch some blind fish in the lake was purely out of luck.

"Hehehe, this should be the perfect diet plan for those middle-aged women with belly fats. Will death come before I lose weight?"

A skeleton laughed with flashing blue eyes. Unable to endure his hunger any longer, Black Mamba started tearing at the seal-like creature's hide. It was chewier than the military leather boots. He'd prefer to eat those instead.

"Pah, pah, I was happier complaining about my misfortune! Kekeke!"

Black Mamba laughed as he spat out the coarse strands of fur. It was fortunate that he had the seal-like creature's hide, at least. Humans don't live to become happy. They are happy to be alive. Someone's words left a deep impact inside his heart.

How comfortable and delightful it was living among modern society above ground! There was clear water, fresh air, green grass, lights that came on with a press of a button, and cooked food that appeared on the table from just opening a wallet. He hadn't experienced real devastation even though he thought he had.

"Nimi Jotto!"

Black Mamba grew hopeless at the sight of a small lake before him, which was around 10 meters in diameter. The cave was blocked. He'd searched everywhere, but there was nowhere to escape. He couldn't detect any space even with his resonance waves. He'd encountered blocked caves several times. They were blocked, but a parasite cave would always appear during his search. He'd forced open a small hole up to 10 times its original size with the billion's water armor before crawling into it.

"No!"

A shout layered with several emotions echoed through the cave. He'd finally arrived, only to… no, this couldn't be it. His heart raced. He ran around like a farm girl in search of her missing cow at sunset. He activated his dimensional sight back on the path where he had come down from with his hands clasped over his hungry stomach and felt each surface with resonance waves. In the end, there was no side cave.

"F***, misfortune's a fortune, this is the end!"

He collapsed onto the floor. He tore the remaining hide he had saved up like dried squid strips and shoved it into his mouth. He chewed on it for a long time and turned it into a soup before storing it in his stomach. Both humans and animals became aggressive and illogical when hungry.

"F***, I'll create my own luck since there is none."

He gritted his teeth and stood up. There was nothing like giving up, despair, or devastation in Black Mamba's dictionary. He'd survived a hellish life for five years since he was nine, after all.

"Should I start digging?"

He looked up at the cave ceiling that remained solidly in place. 200 meters? 300 meters? He had extraordinary strength and the billion's water armor. Time was the only thing he needed to dig through the cave ceiling. At some point, he would reach the surface.

Food was a problem. Unlike blacky that could sustain by combining necessary elements together for absorption, he was a human who needed to eat. The probability of starving to death before digging a hole to the surface was high. It was a foolish approach.

Wait, if there's a lake here, this means water is sourced from somewhere. He suddenly thought.

If there was no water source in the cave, it could mean that there was an underwater passage in the lake.

Splash—

He had already jumped into the lake before he could gather his thoughts.

The cold lake was unexpectedly deep. The longest he could remain underwater was 12 minutes, and the lake of around 10 meters in diameter could be thoroughly searched with several dives.

"Hm, what is this?"

The glowing metal in his hand got brighter. He didn't know whether it was because of the water or some other reason. Finding a hole was breezier with the light. Finding a hole to escape was more important than some strange metal. Black Mamba started searching inside the lake with the unique bright metal.

It's there!

Just when his lungs started trembling, he found a dark passage. It seemed passable as long as he shoved his body in. Happiness overwhelmed his senses and circled his whole body. He wasn't fated to die yet.

Black Mamba scrutinized the metal once he left the lake. The metal had reacted to something. Until now, he'd regarded it as a flashlight that was about to fizzle out and using it without much thought. There had to be a source.

A sniper's eye was different from the average person's. They had different observation skills and a unique ability to characterize objects. That was because their main job was to determine the size of their targets.

The trapezoidal object had a hole in the shape of a flame at the top, which was five millimeters in diameter. The narrow side was one millimeter thick and five millimeters wide, and the wider side was 10 millimeters thick and 10 millimeters wide. Its length was 80 millimeters. It was a poorly crafted ax. No matter how many times he looked, it was a man-made object with personal touches. However, there was no reason for such an elaborate artifact to be several 100s of meters underground. He stroked it with his hand. It was smooth, like silk.

"Hoh?"

The metal turned warm. It was certainly an object that gave off cooling sensations when touched. He tilted his head and shoved the metal between his thighs. That was the warmest part of a human's body.

"Woah! What a funny guy."

The object turned cold like ice. It was so cold that his balls shriveled. A metal that turned cold when the surrounding temperature was high and turned warm when the surrounding temperature was low—he'd never heard of such magic.

He'd been experiencing all kinds of strange and absurd situations ever since he was stuck underground. Well, it was absurd that he was even there. No matter how long he looked, he couldn't tell what it was.

"Well, I suppose time will tell."

He placed the metal between his teeth and bit it before jumping into the lake. The passage was just narrow enough for his shoulder to fit. He pierced the wall with his billion's water armor and pulled his body up. If he didn't get out in 12 minutes, he'd drown to death and remain stuck between the rocks.

Splash—

A dark head emerged. Fortunately, the underwater passage wasn't too long. There was another hole in the area where he stuck his head out. The passage wasn't connected to another horizontal cave.

Hup hoo hoo hoo—

Hup hoo hoo hoo—

He controlled his heavy breathing and searched for an exit. There was none. The hole wasn't that wide, either. There were some developed joints here and there, but no gaps for him to escape through. At least, there was air.

"Damn, I'll have to dig, won't I?"

His impulsiveness exploded. He jumped up from the floor and punched the ceiling with his raging fist.

Crash—

The sound of an exploding cannon rang. Cracks ran down the ceiling. He shoved his hand up to his elbow in between the cracks and pulled.

Crash—

A flat rock the size of a desk fell.

It was gneiss. A gneiss was a type of hard rock in which sedimentary slate had transformed under high pressure and heat. That meant the terrain was sedimentary. Two hands dug apart the gneiss ceiling like crane forks.

Three meters in, his strength depleted. The billion's water armor resurfaced above his skin. That meant it was overworked. He'd have to return to the underwater cave through the narrow passage to soak it. He didn't want to go through any more narrow passages.

"How about this?"

He pulled out the glowing metal. He tried shoving it into the ceiling. It went right in, without much resistance. That was only possible if the metal was like an ultra-vibrating blade that only appeared in the movies. There was no way for a powerless object to create such extreme vibrations.

"What a strange object."

No matter how closely he viewed it, he couldn't tell what it was.

Grrr—

He flickered back into consciousness when his stomach rumbled for food. It ached, as though it was tearing apart. He didn't know how many days had passed since he last ate.

He shoved the metal into the ceiling and created a large circle. A 50-millimeters circle was created. It was just like cutting tofu with a knife. He pushed a finger into the crevice and ripped it off. The efficiency wasn't bad.

"Bingo!"

His work picked up speed. All he had to do was poke around the rock with the metal and rip it off. He felt something cold, five meters deep. He stopped working and sent out his resonance waves. The reflected atmosphere felt different. It felt like there was another space beyond the ceiling. He wouldn't have felt it if the space was small. That meant it was big.

"I see!"

The ends of his mouth slowly curved upward. There was a lake above him. Considering the temperature difference, he had almost reached the surface. The possibility of it being an underground lake was greatly reduced.

What if that was, in fact, an underground lake? The Paranthropus, Black Mamba's life would end. His worries didn't last long. The longer the night, the more dreams. His life would have ended long ago if he was fated to die.

Cra-ack—

He ferociously ripped apart the cave ceiling.

Droplets began to line the ceiling. Cracks started appearing on the solid ceiling. He shoved the metal in and drew a line. Water poured down through the cracks.

Bang—

He bashed it with his head. As expected of his iron-like head, water started pouring and rumbling. Around three to four seconds later, the ceiling collapsed from the cracks. Surprised, Black Mamba jumped and attached himself to the cave ceiling. A person that was once bitten became twice as shy.

Rumble—

The violent lake water poured in. The three-meters tall limestone cave immediately turned into an underwater cave. Immense water pressure pressed down on his body.

Here I go!

He kicked against the floor of the cave and escaped through the hole in the ceiling. It was, as he predicted, a lake. He didn't know whether he was above ground or underground, but the fact that he'd escaped to a wider area was comforting on its own.

What is this?

Black Mamba frowned. The thing that he was stepping on felt strange. Something rustled and shattered. He looked down with the metal in between his teeth.

There were piles of skeletons at the bottom of the lake. The bones, which he had stepped on, shattered. The countless corpses floating around the underground lake and the waterfall that had spat out the corpses from a distant height was finally seen.

Now wasn't the time to worry about the skeletons. Judging by the water pressure, he was 130 meters underwater. Divers' disease? Now wasn't the time to consider that. He'd wasted 11 minutes underwater. His lungs were about to explode.

Woosh—

He kicked against the floor and shot out. The skeleton, which had received the brutality of his strength, shattered. The area from where he took off turned white. The surface of the lake, which had been calm, vibrated.

Splash—

A dark figure jumped out of the lake like a cannonball.