Cave Refuge

Zachary didn't leave with the merfolk at that moment because he could guess that they were probably joining up with the merfolk who had just left and would likely return to the surface to attack the crew of the next ship.

However, it seemed Wave Rider was ranked fifth, and by the time they returned to the surface and used the Illusion Technique on Wave Rider, only to find no one aboard, Zachary didn't know how they would react.

But Zachary didn't have time to consider the merfolk's reaction at that moment, as the most important thing was to first check if there were any other merfolk patrolling around the bubble.

Since his Divine Sense had encountered problems several times, Zachary not only used it to survey the surroundings but was also extremely cautious in observing the environment.

What Zachary hadn't anticipated was that after circling the bubble, he shockingly didn't detect any other merfolk. Either the merfolk weren't worried about the people inside the bubble escaping, or the bubble was enchanted with a spell that only allowed entry but no exit.

No matter the situation, it was troublesome for Zachary because, to be honest, since he was already there, it appeared that the bubble contained captive humans.

In battles with Alien Clans, as long as it didn't affect one's own safety or interests, most normal people wouldn't mind going out of their way to offer a bit of help to others in danger, if it was convenient.

Of course, Zachary wouldn't take action to save them before understanding the situation clearly, and he wouldn't even show himself within their line of sight.

According to classic scenes in movies and novels, if Zachary were to appear before those trapped in the bubble, even if he promised to save them, there would inevitably be some irrational people who would make his presence widely known.

Therefore, to avoid this, Zachary would only attempt to see if he could rescue them from the bubble when he was ready to leave.

Although Zachary wouldn't take action to save anyone at the moment, he still used his Divine Sense to explore the situation inside the bubble, after all, the merfolk had gone to great lengths to capture the crew and bring them here, certainly not out of boredom; there had to be some unknown purpose.

As Zachary had suspected, the bubble in front of him was not as simple as it looked. Although it seemed transparent and didn't obstruct vision, when he tried to use his Divine Sense to penetrate it, he found it was blocked entirely from the outside of the bubble.

When Zachary tried to force his Divine Sense through the bubble, he saw the area of the bubble where the Divine Sense was applied cave in severely, as if squeezed by some force.

Fearing that continuing to exert force might damage the bubble in front of him, Zachary tried from a few different positions, but no matter where he tried, the outcome was basically the same.

Facing this result, Zachary was somewhat helpless and had no choice but to temporarily abandon his initial plan; just as he was preparing to find another method to attempt.

Suddenly, a group of merfolk swam over from a distance, and at that time Zachary didn't know whether the merfolk had come in response to the alert triggered by his touching the bubble with his Divine Sense or for the crew members who had just been brought in.

When the merfolk got close to the bubble, they first dispersed to inspect the bubble and then cast a spell to open a gap in the bubble, allowing the water outside the bubble to pour continuously into it.

Just when Zachary thought the merfolk were doing this to drown the humans inside the bubble, to his surprise, after the depth of the accumulated water in the bubble surpassed around half a meter, the merfolk who had cast the spell closed the gap on the bubble.

At this point, Zachary found the actions of the merfolk rather perplexing; was it meant to torment the humans inside the bubble, preventing them from resting properly?

After all, Zachary didn't believe that the merfolk would build two-story buildings inside the bubble for the captured people. Inside, it probably resembled an ancient prison cell from TV dramas, which, except for not having walls, at most contained only a broken straw mat.

A half-meter depth of water was sufficient to submerge the items that the captured staff had placed on the ground; however, on the other hand, such an act would only cause some inconvenience to the people inside the bubble and would not cause any substantial harm to those imprisoned within. Hence, if this act of the merfolk wasn't maltreatment, what was it?

Yet, Zachary was unaware that the fishman was not doing this to torture, but rather, the merfolk undertook this action to prevent humans from digging tunnels to escape.

The bubble that imprisoned humans underwater, although possessing strong confining capabilities, had a flaw: it could only prevent things from above the ground, not stop those who dug tunnels underneath.

There had indeed been humans caught inside who had attempted to escape from the bubble by digging tunnels, and one of them had successfully led others out.

However, what they hadn't anticipated was that even though they had successfully left the confines of the bubble, they still couldn't escape the region of the Great Whirlpool.

Before they left, they had made plans, assuring themselves that the time they could hold their breath underwater was absolutely sufficient for them to swim back to the surface from the seabed.

But they forgot one thing; they forgot the region where they were. While it seemed that the merfolk moved through the water with natural grace, it was an innate talent they were born with.

Here, even at the seafloor, one was still within the area of the Great Whirlpool. That is to say, invisible undercurrents were present everywhere because water mixes with water, and humans cannot see the pervasive undercurrents underwater with the naked eye.

Humans could only sense the flow of water when their bodies were hit by it, which would then alert them to the presence of undercurrents, but by the time they realized they had encountered an underwater current, it was already too late.

As Martial Artists, they could withstand strong impacts on the ground where they had leverage, but in the water, where there was nowhere to anchor themselves, even a slightly stronger current could sweep them away immediately.

Besides the currents, although there were no merfolk patrols in the vicinity, this place bordered the Underwater City, and it was possible to encounter merfolk passing by from time to time. The moment they left the bubble, the chance of being discovered was nearly ninety-nine percent.

Even if they were extremely fortunate and didn't encounter any underwater currents, nor were they detected by merfolk, and managed to surface in a single breath, the region they were now in was still within the Great Whirlpool.

After all, everyone knows that the shortest distance between two points is a straight line. Although Martial Artists could hold their breath for a very long time, who would have the presence of mind to choose another direction and detour at such a time? Certainly, the first priority would be to surface and take a breath.

When those people managed to surface, only to discover they were still within the whirlpool, and even closer to its center, it must have been a moment of utter despair.

But in reality, although some people managed to escape from the bubble, not a single one succeeded in reaching the surface; the undercurrents of the Great Whirlpool were everywhere from the surface to the bottom.

Apart from the merfolk, whose racial talents naturally equips them, even those creatures that appeared in the water after natural disasters could not survive in this zone filled with currents.

It is for this reason that the merfolk, even though they had previously experienced their captives breaking out, still did not arrange for guards to patrol this area.

However, to prevent others from escaping through tunnel digging again, the merfolk thought of a rather simple solution.

If anyone inside attempted to escape by digging tunnels again, no matter how well they hid their activity, the absence of waterproofing tools meant that half a meter of water was enough to inundate and collapse those tunnels, especially since the geology at the bottom is mostly mud and sand--easy to dig through but also easily collapsible upon contact with water.