Lowering his body, Su Mo attempted to forcefully turn the control wheel located next to the motor-pumped oil well.

When the wheel had reached its maximum rotation, the shaft of the oil well began to tremble.

After some time, the tremors subsided and the oil well gradually returned to its peaceful state. 

Gurgling sounds could then be heard from the five gigantic pipes and the hum of the diesel generator added to the cacophony; the sound vibrations were almost headache-inducing. 

A simple display screen, about the size of a palm, popped up automatically next to the oil well. It listed all the items that could be produced by the oil well as well as its production efficiency. 

All you had to do was select an item, press the 'confirm' button, and the motor-pumped oil well would produce it continuously for the next twenty-four hours!

As a test, Su Mo selected diesel and toluene, the two things that he urgently needed at the moment.

Chug!

When the selection was completed, the display retracted into its original position.

Frantic rumbling sounds began emitting from the pit of the oil well and the diesel generator's movements also created noises that could be heard from the wellhead.

"Oh no, this thing is way too loud. It would be fine if this place was enclosed, but with a hole here, the noise will definitely be detected and attract ill-intentioned people." 

Su Mo perched himself on a storage box as he tried several methods to reduce the noise coming from the oil well, including putting a cover over it, but nothing worked.

As he walked over to the door, the sound became weaker, but it was still clearly audible.

After spending a moment in thought, a thought came to his mind.

"It seems I'll just have to..."

"Include shelter number two as part of my territory!"

Thinking that, a gleaming turtle armor appeared in Su Mo's hand. It was the core of an entire safe house which had dropped when the man with glasses had been killed previously. 

A damaged safe house core could be directly integrated into the shelter to increase its surface area.

With a complete core, though, you could build a new shelter instantly, either above ground or underground.

"I had originally intended to save this as my trump card, but now seems like the right time to use it!"

Slowly, he rubbed on the top part of the turtle armor. A holographic prompt appeared:

[Record]: Player "Su Mo" is detected to be the current owner of this shelter...

[Record]: Authority detected and approved!

[Record]: Confirm usage of the complete safe house core, recast the ownership of the current shelter, and bind it to the game panel!

The three prompts were displayed one after the other. After confirming that it was all in order, Su Mo gently said, "Yes". The turtle armor began changing colors and melted in his hand.

The melted liquid from the turtle armor trickled to the ground. Gradually, sounds began resonating through the shelter. 

Like the caress of flowing water, or gentle waves cascading on the shore. 

Like a storm that was tearing through the sky, or a monstrous tidal wave that crashed against the surface of the sea.

With his eyes closed, Su Mo seemed to feel as if he was on a lone boat out at sea. 

Below the surface of the sea, sharks circled around the clusters of overgrown reefs. 

He opened his eyes and the illusions disappeared.

"What magical sounds! I seem to have heard something similar before..."

Su Mo scratched his head, sat down on the storage tank, and continued to wait.

When he upgraded his buggy previously, these sounds could also be heard from the shelter. 

Now, as he set up the integration authority for the shelter's core, the sounds reappeared. They were clearer and louder this time, creating unbelievable effects.

Taking advantage of the period required for the integration of authority, Su Mo closed his eyes once more and returned to his illusion at sea while the sounds caressed him.

Compared to building an instant shelter, the speed of this integration was significantly slower.

After waiting approximately half an hour, during which the sounds had resonated back and forth, the prompt reappeared on the game panel. 

[Record]: Player "Su Mo" has bound "2" shelters. Please designate the primary and secondary shelters. 

[Record]: Please designate the sequence carefully. Once completed successfully, no further changes can be made and some functions will differ from before. 

"Huh? Primary and secondary shelters?"

What popped out was not the original prompt for the completion of the binding process, but rather a prompt asking him to designate the primary and secondary shelter settings on the game panel.

Su Mo tried skipping this prompt, but the game panel was being sneaky. The option to close it was unavailable.

The prompt was locked on the game panel. It seemed impossible to proceed to the next step before completing it.

After four or five attempts, Su Mo gave up on the idea of finding a bug in the system. He could only follow the game panel's instructions accordingly and make his selection.

"Which shelter should I set as primary? Mine or this one?" 

"What are the differences in functionality? Is it possible that the secondary shelter cannot be upgraded? That wouldn't make sense!" 

Observing the malfunctioning alloy door, Su Mo sat on the storage tank in deep contemplation. 

If it was necessary to designate a primary and secondary shelter, the future development of both shelters had to be considered comprehensively.

In terms of safety, shelter number one was definitely better than shelter number two. 

Shelter number one was submerged five meters underground with only one exposed door, making it an ideal underground shelter.

However, shelter number two was different. While it was also an underground shelter, its development path was completely different.

It was just surrounded by a cluster of small hills. Upon exiting the current main door on the second floor, you would only have to walk down a short path downhill before reaching the ground.

Strictly speaking, shelter number two appeared more like an above ground shelter, and could be expanded laterally when the time comes for development. 

"I can bring back the thermal weapon machine from shelter number two. I can also take all these little things with me too. The motor-pumped oil well is probably the most valuable thing here. It is definitely something that cannot be relocated and I'll have to rely on it to produce energy in the long run."

"Just one motor-pumped oil well?"

Su Mo stood up as realization dawned.

Staring at the oil well behind him, his mind raced. Without hesitation, he selected shelter number one as the primary shelter.

Given that there was no other advantage to shelter number two other than the motor-pumped oil well, why would he choose it?

With the survival system in place, it would not take long for shelter number one to develop into a stronger and safer shelter than shelter number two. 

It was not necessary to give up the fundamentals!

After Su Mo confirmed the selection on the game panel, the glow vanished and the dialogue box disappeared.

A new interface popped up!

[Record]: Congratulations! Player "Su Mo" has successfully integrated and bound the second shelter.

[Record]: Congratulations! Player "Su Mo" has earned the "Second Level 5 Shelter" achievement and automatically receives a chance to draw a lottery.

[Record]: "Transcendent" properties are detected at the secondary shelter and automatically copied over to the primary shelter.

[Record]: A large difference in level has been detected between the primary and secondary shelters. The secondary shelter has received a one-time authority reparation adjustment.

[Record]: The secondary shelter's level will be permanently locked. There will be no core integration upgrade. Transcendent properties will be permanently locked. The shelter will not receive transcendent blessings and upgrades.

[Record]: Player "Su Mo" has been detected to own more than "1" shelter. The game panel will open the prompt automatically.

[Record]: A durability prompt will automatically appear if another player damages or destroys the primary and secondary shelters. When the durability drops to 0, the shelter's properties will automatically be removed from the game panel.

Seven prompts flooded the interface, like a tide of water rushing in. 

Su Mo began reading the first prompt. By the time he had read the last prompt, his face was plastered with an uncontrollable smile. 

This could have been considered to be the right move! 

"The chance for one lucky draw has been stored. All prompts have been read." 

After those words were delivered, all the prompts vanished and a whole new interface appeared in Su Mo's vision.

While the primary shelter had a soothing green interface, the secondary shelter featured an energetic sky-blue one. 

It was not a shade that would hurt your eyes like neon blue, but rather, it looked like seawater flowing across the interface. 

The fine lines of water vibrated in response to Su Mo's thoughts. 

A small panel popped up and Su Mo was requested to name the shelters.

"They were always called number one and number two, which doesn't sound good. Might as well imitate the Tundra shelter and rename my shelters as well."

"Well, for Shelter Number One... From now on, it will be called the Underground Shelter. It is simple, easy to remember, and accurately describes its characteristics. As for Shelter Number Two..."

Su Mo carefully examined the environment of Shelter Number Two, staring at the background, which had yet to display any properties. Tiny bits of inspiration began to emerge:

"Shelter Number Two will be called... the Deep-sea Shelter."

After Su Mo confirmed the shelter's name, the game interface panel trembled for a short while for some unknown reason, as if it was happy to have its name.

The following second, a panel containing all of its properties appeared. Su Mo was stunned when he read it!

[Deep-sea Shelter (Secondary)]

[Level]: Lv 5 (Locked, cannot be upgraded)

[Description]: An underground shelter made entirely of cement that possesses a highly rigid architectural structure. The main door of the shelter is made from alloy and is extraordinarily strong. The building has upper and lower floors with excellent functionality. 

[Space]: 220㎡*2 (Storey height 4.2m)

[Integrity]: 89% (Damage has been detected in small areas)

[Facilities]: Small thermal weapon machine, level three alloy main door, motor-pumped oil well...

[Transcendent Ability]:

Transcendent property: Repels Water (Lv1)

Source: For "unknown" reasons, this shelter has been blessed by the Mermaid Clan of the Deep-sea Fantasy World. It has a marginal ability to protect from water. A water-repelling membrane will be applied automatically in the case of a water attack, creating an isolation bubble that prevents water from entering.

[Available authority]: Reparation. Provide 22 damaged shelter cores to transfer any floor of this shelter to the primary shelter with immediate effect. Its surface area will change according to the attributes of the primary shelter, not exceeding the maximum of 220㎡.