Su Wu didn't hesitate for long before deciding to add a new batch of weapons.
Considering that they might face more enemies this time, simply adding guns or rockets wouldn't be cost-effective, nor would it provide an overwhelming advantage.
After searching the database for a long time, Su Wu finally came up with a new plan—making thermite.
Thermite is a mixture capable of producing temperatures exceeding 2,500 degrees Celsius when burned, enough to melt steel in a very short time.
Its primary ingredients—aluminum powder and rust—are both extremely common and inexpensive.
But its power is terrifying.
No matter how strong the defenses, once burning thermite makes contact, there is no escape from being burned through.
The only drawback is that it burns in a very small area.
However, solving this issue is simple—just add a small explosive charge or fireworks to the thermite to expand its destructive range.
As for the delivery method, Su Wu chose two options: using drones to drop the bombs directly or making them into shells to be fired from a howitzer.
Both options are extremely low-cost.
Drones could be substituted with K2-series agricultural drones, while the howitzer, though needing to be built from scratch, was far simpler than complex automated machinery like micro excavators. It required only some specific materials.
The engineering robots could manufacture it entirely—there was no need to use precious survival points.
"Once the small bunker is built," Su Wu thought, "a 120mm howitzer can be placed on it."
"Stock 20 crates—160 thermite shells in the corresponding specifications."
"As for the thermite bombs for drone deployment, produce 50 units each in two sizes: 20 kg and 40 kg."
Since thermite's raw materials were both common and cheap, Su Wu was quite generous in planning his ammunition reserves. He based his calculations on achieving a saturation strike lasting over 10 minutes.
Now, the shelter's firepower configuration was more than sufficient—excessive, even.
Not to mention that the Irving Shelter, his theoretical enemy, was only a mid-sized corporate shelter with just over 10,000 residents.
Even against a full company-level military unit, his firepower wouldn't be at a disadvantage.
Yet, despite all this, Su Wu still didn't feel safe enough.
His gaze fell on the three-dimensional map of the shelter, specifically the vertical drone lift channel that connected the shelter to the small bunker that had yet to be built.
A new idea emerged.
Since there was already a ready-made vertical launch silo, why not make a bigger one?
He opened the database and conducted a quick search.
A design schematic for a 240mm-diameter rocket appeared.
The production of related military weapons was now officially added to the engineering robots' workload.
Checking the time, he noted that the concrete of the first level of the small bunker on the surface should have almost hardened.
Su Wu dispatched all eight construction robots, along with a concrete mixer truck and a mini excavator, from the engineering team on the fourth underground floor to continue building the second level.
Compared to the nearly six-meter height of the first level, the second level would be only about three meters tall, meaning the workload was significantly reduced.
With the combined efforts of the eight construction robots, the estimated completion time was just two to three hours.
Then, after approximately eight hours of hardening, they could proceed with building the third level and sealing the structure—at which point the entire small bunker would be complete.
With internal matters settled, Su Wu resumed commanding the convoy in the city to clear roads.
By evening, after more than five trips back and forth, the large transport trucks had moved hundreds of tons of construction debris back to Su Wu's shelter.
At last, the first passage leading to the nearest official shelter entrance was fully cleared.
Without delay, Su Wu controlled a construction robot and rushed to the official shelter's supply warehouse to retrieve his stored materials.
"The supplies you deposited here include 220 tons of steel and 300 tons of fertilizer," the warehouse manager reported.
"But..."
The manager hesitated.
"What's the problem?"
Su Wu raised an eyebrow. His voice, transmitted through the construction robot, sounded cold and sharp.
"Nothing. I'll process the pickup right away."
The administrator seemed to realize that his hesitation was inappropriate and quickly put on an apologetic expression.
Lowering his head, he printed out a delivery form from the computer and handed it to the construction robot under Su Wu's control.
Then, after a moment's hesitation, he couldn't help but add,
"You'd better collect all your stored supplies before tomorrow morning."
"I heard from our supervisor that the shelter is experiencing a shortage, and they're considering temporarily requisitioning materials from the public to fill the gap."
"If you're too slow, you might end up with nothing but an IOU."
For a low-ranking administrator like him, such actions by the upper management weren't necessarily beneficial. On the contrary, they could be a disaster.
He would be the one facing angry civilian shelter representatives who had just lost their stored supplies—bearing the brunt of their fury.
If things escalated, he might even bleed for it.
The administrator stole a glance at the steel-structured robot before him and felt even more bitter.
A shelter that could afford to operate robots clearly wasn't an easy target. Producing firearms was probably as easy for them as playing a game.
If a conflict broke out, no matter what happened to the other side, he would definitely be the first scapegoat.
"Requisitioning supplies?"
Su Wu wasn't surprised by the news. His aggressive effort to clear city roads had been precisely to prevent this sort of situation.
In a highly centralized system—especially in the early days of an apocalypse, when peacetime constraints weakened—it was perfectly normal for the powerful to tear up agreements and oppress the weak.
Receiving an IOU was already considered an act of mercy.
"I see. Thanks for the warning," Su Wu said calmly.
"I'll collect the rest of my supplies before seven o'clock tomorrow morning."
Hearing this, the administrator sighed in relief.
"That's good. There shouldn't be any issues before seven. Our supervisor won't arrive that early."
To him, this was one less problem to deal with.
After receiving the outbound delivery form, Su Wu oversaw the loading process.
With the help of several forklifts operated by official shelter workers, 20 tons of fertilizer were loaded onto a large truck in less than an hour.
Watching through the surveillance feed as the truck made its way back along the cleared streets, Su Wu fell into deep thought.
He needed to carefully consider his next move in response to this unexpected situation.