Weaver and Drone 7 were standing in front of Custodian when it woke up. The production drones were still churning out products, and the conveyor belts moved as usual. It seemed that whenever Custodian ‘listens’ to the memories, only the A.I. would fall asleep.

“How long have I been out?” Custodian asked when it realized that the rest of the raid team was gone.

“A few hours,” Weaver replied.

“Where is the human corpse?” Custodian inquired.

“You processed it, Master Custodian,” Drone 7 replied.

Custodian nodded as it checked its storage. It seemed that not only were humans good sources of mana matter, they were also good sources for biomatter.

“Do you two need something?” Custodian asked.

“I have successfully deciphered the human language to a basic level. I could somewhat converse with them now, and get useful information,” Weaver reported.

“That is good. What about you, Drone 7?” Custodian turned to the other drone.

Drone 7 raised a glass filled with reddish liquid. “I have created a concoction. When shocked, it would explode approximately three seconds later.”

“Interesting. How did you make this?” Custodian inquired.

“I grinded a small amount of anti-mana, then mixed it with powdered skeleton monster cores. After that, I added blood from the spiked rats,” Drone 7 explained. The spiked rats were the new type of rats encountered by the drone when the rats tried to wipe out the automatons. Apparently, they served as alphas of small groups of rats, and they possessed some intelligence to lead raids against Custodian’s hunters.

Despite the rat population regaining its numbers, they were still being kept in check by the sentry turrets and the patrolling combat drones.

“That is good. Continue experimenting with substances. I name you Apoth.” Custodian dismissed the two drones as it began concentrating on its next plan.

Currently, its forces were insufficient to do anything major. In order to push forward, Custodian would have to advance Protocol 4C, the protocol which led to new processor designs.

‘The human heart has quite a number of mana matter. I wonder if I could get more later…’

Custodian was stockpiling anti-mana in order to advance Protocol 1, but it didn’t expect that the human heart would give so much boost.

It seemed that the heart would be the equivalent to a monster core, but was still different from one.

‘Should I…’ Custodian thought deeply for a moment. ‘No. They are still useful. It would be counterproductive to sacrifice long term gain for short term gain for now as I had calculated earlier.’

In the end, Custodian decided to allocate all of its concentration on production. All activities within the ruined city ceased as Custodian didn’t want any drones being destroyed for no gain.

Meanwhile, back at the pool chamber, Weaver was starting to get the hang of the human language spoken by Gerard and all his group.

“Elena… black hair. Why?” Weaver pointed at the priestess. It was trying to figure out if Elena’s hair was different because her model wasn’t the same as Gerard’s.

“Oh, you see, everyone but Elena is from Vyssium. Almost all Vyssians have red hair, which is also why Vyssium is called the ‘Land of Autumn’,” Gerard explained.

“Vai...See-Yum… your home name. This place. What name?” Weaver asked as he pointed at the ground.

“This place? I wouldn’t know,” Gerard shrugged.

“Get in here… how?” Weaver probed.

“Through the tower. I can show you where it is in the ruined city if you let me out,” Gerard offered.

“No. We know where. How you get in here?” Weaver asked once more.

Gerard was really confused. He saw that these people had been scavenging the ruined city, and that this whole place was desolate. Not only that, they acted as if they came to this place from another way.

Perhaps on the other exit of the room, there was another underground city? How else would anyone survive here?

In the first place, having grasslands underground was inconceivable. Were these people born underground? So many questions…

“If answer, I give… this.” Weaver took out a bag of rat meat.

“Again… do these people just live off rat meat?” Gerard muttered. It had been a few days since they were rescued, and since their rations ran out, the drones had been providing them with rat meat to survive.

Gerard was about to take out a map when Aefelred stopped him. “What are you doing, boy?”

“I’ll show them how we got here… and why,” Gerard replied.

Aefelred pulled the young man away from Weaver then whispered, “I don’t trust these people. They might not even be humans.”

“How can you say that? They risked their lives to protect us,” argued Gerard.

“Remember the Vyssian saying. A farmer fattens his cows for a better steak,” Aefelred reminded.

“So you’re saying they want something in return? We don’t have anything but the map. Besides, I bet if we give them this map, they’ll let us out,” said Gerard.

Aefelred thought deeply for a minute, then sighed. “Fine. I hope you made the right choice.”

Weaver was approached by the two men once more. With great reluctance, Gerard showed the drone a map.

“Back in Vyssium, we found this map by chance. It detailed that under a mountain, there was an abandoned city with a weapon that could get us a fortune. We didn’t expect the city to be filled with undead,” Gerard explained as he gave the map to Weaver.

“This… Us under mountain?” Weaver asked.

“Yes. This is place is under a mountain. We used the map to find the path to this place.”

“This place… much danger. Why not leave?” Weaver looked up from the map then tilted his head.

“We… couldn’t. There was a one-way barrier we couldn’t detect until it was too late. In the end, this venture doomed us all. It even costed us one of our own life.” Gerard gave a depressed sigh as he thought about his fallen comrade.

“Hmm.” Weaver simply nodded his head.

“I know this is pushing it, but if possible, can I ask for your help to recover her body?” Gerard begged.

“Maybe.” Weaver shrugged. He didn’t want to tell the humans that they already processed her corpse into building material.

Dyvona walked up to Gerard as she held a spider drone. “Can you ask him what this is? It’s so… wow. I really don’t know what this is. It’s not an animal, I think…”

“Please put down.” Weaver stood up and grabbed the drone from Dyvona’s hands before placing its kin down.

“S-sorry. I just find the little things to be so adorable and interesting.” Dyvona laughed as she scratched her red hair.

While Weaver was processing what ‘adorable’ means, Custodian was studying the map given by Gerard. Detailed in it was a general location from above, then a rough sketch of the city landmarks.

‘I see. It seems we have much work to do,’ Custodian noted in its mind as it looked at the strategic points. Cross-checking with the information obtained from the scout drones, Custodian was able to formulate an accurate map, and many optimal paths within the city.

While the spiderlings were forbidden from entering the city until Custodian could get better processors, the raiding team was free to do as they wished.

By now, Slayer had discarded his fur armor and replaced it with steel chainmail made by Smith over a thick red silk robe. While silk is tougher than steel, it was hard to obtain from the spiders. There were silk collecting drones, but they were extremely limited in their movements, thus Weaver still had to collect the silk by himself.

Not only Slayer was given armor, the rest of the raid team also had better equipment except for Princeps, who was already carrying advanced gear such as a full plate of armor.

Magus, in particular, wore a full silk robe adorned with torn red banners he had acquired from numerous raids, while Apoth wore a simple chain shirt with a leather pouch for his glass bottles.

With better equipment, the raid team was able to challenge smaller groups of living armor in order to contest for the guarded barracks scattered across the city.

This was also preparation for the inevitable. Eventually, they would have to fight for the fortress to get to the surface.

When Custodian finished analyzing the map, the raid team was immediately put to work. They began clearing the path, killing every undead on their path, street by street. They were meticulous, trying not to provoke the wrath of every single undead in the city, but still kept a steady pace.

Every time the raiders returned, they came back with bags full of bones and monster cores.

Of course, the humans caught sight of this.

“Mister Gerard, what do you think they’re doing with those bags of bones?” Elena asked.

“I don’t know. It feels like everything they do is an unsolvable mystery,” Gerard replied.

“Ever since you gave that Weaver fellow the map, they’ve been venturing into the city more and more,” Aefelred observed.

“Do you think that they’re…” Gerard muttered.

“Indeed. It looks like they’re clearing the way to the lord’s castle!”