A secondary team, with the blueprints ready, went to the coast to build a ship.
In order to obtain information about the outside world without alerting the Marleyan government, they had to use their own strength to leave Paradis Island and witness this vast world.
This place was located hundreds of kilometers in a straight line from Marley's port, so the probability that enemy soldiers would discover the shipbuilding and testing operations carried out here was relatively low.
Although the risk was low, Gale did not dare to take it.
This was not something to gamble on. If they lost the advantage they currently had over their enemies and the Marleyan government realized that something was wrong and spread the "threat of Paradis Island" internationally, then the nuclear program Gale was immersed in would end before it even began.
If that happened, the war would reach a point where Gale would have no choice but to use the Rumbling.
However, compared to a fully functional nuclear missile launch system, the deterrent power of the Rumbling that Eren once used was insufficient.
The tactic of using the Rumbling, if not deployed on a large scale, actually has a very limited effect.
First of all, the Colossal Titans within the walls must move on foot to subdue the enemy army.
If the full deterrence maneuver of the Rumbling, capable of shaking the earth, were deployed on a small scale, the Colossal Titan would destroy everything in its path, which is unsustainable from a "humanitarian" point of view.
If other governments outside learned about the use of Colossal Titans to crush Marley's army, it would not take long for someone else to declare war on them.
As for Gale's people, they would only defend themselves by claiming that Marley crossed their territory and killed their people. This would only intensify international hatred toward Paradis Island, making it increasingly difficult to resolve and ultimately turning it into the target of everyone's wrath.
Furthermore, assuming the army moves constantly during the campaign, changes in the routes of the Colossal Titans would result in an increasing number of innocent casualties.
Innocent lives that Gale does not want to see entangled in his desire to win the war.
Secondly, only those who possess the power of the Founder can activate the Rumbling.
In the current era, Eren and Dina have broken the vow of non-aggression of the 145th King, but what will happen afterward?
If they rely solely on the power of the Titans, when Eren's thirteen years of life come to an end, no one can guarantee who the next holder of the Founding Titan will be, nor who will inherit it afterward.
Once Eren's life comes to an end, everything will become uncertain.
Let us consider an extreme hypothetical scenario: what would happen if the holder of the Founding Power died after Gale's ultimate weapon had been developed?
Those Colossal Titans—let alone being used as weapons—would simply lose control and attack humans indiscriminately.
The extinction of all humanity would not be impossible.
In that scenario, only wandering Titans would remain on the planet.
This was even something Eren thought about when he used the Rumbling to kill 80% of humanity—such a monstrous act.
It is like a person facing the trolley dilemma, already mentally unstable, choosing to kill everyone just so the people they care about can survive.
However, now there is a better way.
If Gale could manufacture nuclear bombs and demonstrate their power to the world, then there would be room for "diplomacy."
Instead of relying on the power of Titans as they have until now, he would use machines and technology that humans could understand to demonstrate the military strength of Paradis Island.
When the world feels fear of nuclear weapons, that will be the moment when Paradis Island becomes a powerful nation, and only then will they have the right to sit at the negotiating table and use diplomacy to improve relations with other countries, instead of being unilaterally declared at war by them.
Unlike the Rumbling, nuclear bombs do not have many insurmountable limitations.
Therefore, it is necessary to build nuclear weapons.
However, although Gale does not need to study the structure and principles of nuclear bombs, he must have an industrial system capable of supporting the various parts and materials that compose them.
Given the small population of Paradis Island, even with "special Titans," it would be extremely difficult to reach that level in a short period of time.
Therefore, it is necessary to build ships and seek opportunities in the outside world.
Reinventing the wheel makes no sense.
Since the outside world already has the technology and industries they need, they should find a way to use them.
Thus, at the end of December 846, the construction of the shipyard officially began.
The shipyard was located underground, not on the surface.
They used Titans to dig underground, excavating a subterranean shipyard inside an unnamed mountain along the coast.
Eight hundred Titans, equivalent to eight hundred heavy intelligent robots with unlimited energy.
After taking turns basking in the sun to replenish their energy, the eight hundred Titans picked up shovels and used steel bars, cement, and other construction materials transported from within the walls to rapidly build an underground shipyard.
Their efficiency was terrifying.
Titans were practically laborers by nature.
Capitalists would drool over them.
This tool was far better than a worker; it asks for nothing, and yet works tirelessly for you.
…
In March 847, they had created an "artificial underground cave" in just four months.
The underground shipyard has a total constructed area of 14,000 square meters, including 3 large caverns, 16 pathways, guide tunnels, diversion tunnels, shafts, and more.
The largest shipbuilding cavern is 75 meters high.
This 75-meter-high cavity was excavated by Titans.
The light source of the underground shipyard is "Titan mineral," extracted from beneath the Reiss chapel.
That is the place where successive kings of the walls held their power succession ceremony.
Those minerals that glow automatically were extracted, placed into specially made glass containers, and used as a light source.
The principle behind the luminescence of this mineral is unclear, but it can provide bright light almost indefinitely.
They are not radioactive light sources; the light they emit is harmless to humans, as demonstrated by Rod Reiss's good health.
According to Rod, the Reiss family prayed weekly at the ritual site. High-ranking members of the Wall Church, some important nobles, and military police also went to that underground place during major religious festivities. And as far as was known, in the past hundred years, no one had suffered health issues.
"That is a sacred place created by our ancestors," the old Rod replied when questioned.
"It's finally finished." Gale sighed in relief. He removed the safety helmet made of rattan and looked up.
This was the largest shipbuilding hall in the underground shipyard. As far as the eye could see, an endless arched dome stretched out.
The dome was made of cement and reinforced with thousands of scale-like steel plates using anchor bolts.
Beneath the silver-white dome, "mineral lamps" hung neatly in place—hundreds of them emitting bright white light, illuminating the underground shipyard, which was as large as a football field and as bright as daylight.
Those glowing crystal domes, like hanging stars, were so dreamlike and beautiful.
It wasn't just Gale who stared at that futuristic space; Hange, Eren, Dina, Hannes... all the workers involved in this project, and even the Titans waiting in a corner, were stunned by the scene.
"It's really been built..." Hange murmured in disbelief, "It's like a dream."
It was like a dream; that was the best way to describe what everyone present was feeling.
Everyone held their breath, afraid of suddenly waking up from their dream.
But they knew for certain that this was not a dream.
Because this underground shipyard was a miracle they had created through their daily work, using the strength of the Titans and the mind of a single person—Gale Hawthorne, who was regarded on Paradis Island as the father of innovation.