Investing in My Harem in the Apocalypse Makes Me Stronger

Cain walked toward the hidden doorway.

Beyond it, a narrow stone passage descended beneath the warehouse. Dark stains marked portions of the floor, while shallow channels had been carved along either side of the path.

His pupils gradually turned golden.

Through Dragon’s Eyes, faint traces of Mana immediately became visible inside the channels.

Most of the energy had already dispersed, but enough remained for Cain to tell that something carrying a considerable amount of Mana had once flowed through them.

And whatever it had been, the channels led deeper underground.

Cain’s expression became more serious.

”Stay alert.”

He entered first with Elara following close behind. The others came after them, their earlier excitement over the Blood Crystals noticeably subdued by the strange passage beneath the warehouse.

The farther they descended, the stronger the stale smell became.

It was not the rotting stench Cain had grown accustomed to since the apocalypse began. There was something dry about it, as though whatever had died down here had been left untouched for a very long time.

Cain kept Dragon’s Eyes active.

Even though Cain could not sense any living presence ahead, he still did not lower his guard.

The passage eventually ended before another reinforced chamber. The heavy door had already been left partially open, leaving enough space for a person to enter without forcing it apart.

Cain pushed through first.

The moment he stepped inside, he understood where the smell came from.

Several dried corpses lay against the walls.

The others entered behind him before stopping one after another.

The corpses were old.

Most had been drained until the remaining skin clung tightly around their bones. Others had decayed much further, leaving little besides dried tissue and skeletons behind.

What unsettled the group more was obvious.

None of them looked human.

Cain’s gaze settled on one skeleton near the wall. Its arms were unnaturally long compared to the rest of its body, and the arrangement of the joints was unlike anything he had seen before.

Nearby, fragments of unfamiliar armor remained attached to another corpse.

The shape alone was enough to show that it had never been designed for a human body.

Cain continued deeper into the chamber.

Then he stopped.

A much larger corpse rested against the far wall.

Even in its collapsed position, the body was enormous. Its bones were considerably thicker than those of the other corpses, and one dried arm alone looked large enough to belong to something several meters tall while alive.

Cain’s eyes narrowed.

The sight immediately reminded him of the battlefield they had crossed earlier.

The gigantic skeletons scattered across the ruins had possessed proportions no human could match. Even their broken weapons had been absurdly large.

The Giant Race.

Cain could not tell whether the corpse before him belonged to the same Race. There was too little left to make that conclusion with certainty.

Still, the resemblance was difficult to ignore.

Behind him, Evelyne had become unusually quiet.

Her attention was fixed on the floor.

Cain followed her gaze.

The same shallow channels they had seen in the passage continued throughout the chamber.

Several ran beneath the corpses.

Dark stains had accumulated inside them before continuing toward the passage leading back to the warehouse.

Toward the unfinished Blood Crystals.

Professor Irina slowly crouched beside one of the channels.

She touched the dried residue along the edge with the tip of an arrow before quickly pulling it away.

Her face gradually lost color.

”This isn’t storage.”

Sonya looked toward her.

”What do you mean?”

Professor Irina stood again, her gaze moved across the corpses before returning to the channels beneath them.

”This chamber is connected to the place before.”

Silence followed.

For a moment, nobody seemed willing to say what that implied.

Then Evelyne looked back toward the passage.

”The Blood Crystals...”

Professor Irina nodded slowly.

”The description said they contain blood essence.”

She looked toward one of the dried bodies.

”It had to come from somewhere, right?”

The atmosphere inside the chamber became noticeably heavier.

Cain had already known that the Zombie Blood Crystals were artificial resources.

Their description had clearly stated that the Zombie Race refined blood essence together with other forms of energy to create them.

He simply had never considered where that blood essence came from.

Now the answer was directly in front of him.

The Zombie Race was not simply killing whatever entered the Invasion Corridor.

They were taking the remains afterward.

The corpses of other Races were brought here and drained, with whatever could still be extracted from their bodies fed into the refinement process.

Those resources were eventually turned into Blood Crystals.

Resources that strengthened the very soldiers invading other worlds.

Maya’s hand tightened around the grip of her sword.

”That’s...”

She stopped before finishing.

There was little she could say that the others were not already thinking.

Jack stared at the enormous corpse near the wall for several seconds. His usual relaxed expression had disappeared completely by the time his gaze returned to the channels.

Even Ron had nothing to say.

Sonya eventually looked toward the passage behind them.

”So the Blood Crystals we just found...”

Professor Irina answered quietly.

”They were probably made from beings like these.”

Sonya’s face twisted.

Evelyne looked even worse.

She had spent much of the apocalypse surrounded by corpses already, but this was different.

Those people had not simply died.

Their bodies had become ingredients.

Cain understood why the others were disturbed.

He also did not like what he was seeing either, but standing here feeling disgusted would accomplish nothing.

”We’re still taking the crystals.”

Several people immediately looked toward him.

Sonya hesitated.

”I know they’re useful, but now that we know where they came from...”

Cain glanced toward the dried corpses.

”They’re already dead.”

His voice was calm as he continued, ”Leaving the crystals behind isn’t going to bring any of them back.”

Sonya fell silent.

Cain turned toward the others.

”What happened here is already done. We can’t change it.”

He paused briefly before continuing.

”What we can change is whether the same thing happens to our world.”

The expressions around him shifted.

Cain looked toward the enormous corpse again.

They still knew almost nothing about its race.

Maybe its world had already fallen.

Maybe whoever this person had once been had entered the Corridor for the same reason Cain’s group had.

None of that mattered anymore.

The corpse was here. Drained and forgotten beneath a Zombie Race outpost.

Cain did not intend to let Earth end the same way.

”Our families are still outside... The people we care about are still there too.”

Nobody interrupted him as he continued.

”If these resources can make us stronger, then we’ll simply use them.”

Cain’s gaze became colder.

”I’d rather use what the Zombie Race made to kill them than leave everything here for the next group of soldiers.”

Elara nodded in resolute.

”We came here to stop the invasion anyway.”

”Exactly.” Cain looked around the chamber. ”Getting stronger is part of that.”

Jack glanced toward the dead again.

”Then we make sure nobody from Earth ends up in a place like this.”

Cain nodded.

”That’s the point.”

The uneasiness on Evelyne’s face had not disappeared, but she released a slow breath and looked away from the corpses.

Sonya remained quiet for another moment before eventually nodding as well.

Cain did not try to convince them any further as they had seen enough.

”Let’s go.”

The group returned through the passage.

Nobody spoke much during the climb back toward the warehouse.

When Cain saw the Blood Crystals again, they looked exactly the same as before.

Only now, everyone understood what had gone into creating them.

Cain stored all of the completed crystals inside his Inventory.

Whatever discomfort they felt about their origin could wait.

Those resources would help make them stronger and that was what matters the most.

They continued searching the outpost afterward.

The remaining smaller structures offered little worth taking, but one building near the center stood out immediately.

It was larger than the barracks and constructed from darker stone. A strange symbol had been carved above the entrance, resembling several of the markings Cain had seen on the map recovered from the previous camp.

Nathan looked toward it.

”Command building?”

”Probably.”

Cain pushed the door open.

The interior confirmed Nathan’s guess quickly enough.

Several dark tables occupied the room, covered with documents written in the same unfamiliar language they had encountered earlier.

Cain picked one up, but nothing happened.

He touched another page and still nothing happened.

Dragon’s Eyes could reveal information about many things, but apparently translating an entire language was beyond what the talent offered.

Cain clicked his tongue.

Ron picked up one of the papers and turned it upside down.

”They really need to start dropping translation skills.”

Cain glanced at him.

”That might be the smartest thing you’ve said today.”

”Fuck off!” Ron snorted as he slowly lowered the paper.

Cain chuckled lightly.

He then shifted his attention toward the far side of the room as something there was still emitting Mana.

A large black device rested against the wall.

Its construction was unlike anything they had seen inside the other buildings. A dark-red crystal had been embedded near its center, while thin lines of Mana pulsed across the surrounding material at regular intervals.

Apparently, it was still active.

Cain immediately became more cautious.

He approached slowly and studied the device through Dragon’s Eyes first.

There was no obvious danger as only a stable stream of energy moved through the structure.

Cain placed one hand against its surface.

Information appeared before him.

[Zombie Race Corridor Communication Device]