To say that this process had been difficult would be the understatement of the century, but he'd finally made it to the other side.

He laid on the beach as the waves washed over his body, and a faint smile appeared on his face.

After suffering through so much hardship, had he finally succeeded?

He laid completely still, concealing his soul power in its entirety while burrowing into the sand like a sea turtle. At the same time, he was regulating his own temperature so he wouldn't be discovered by the Northsea Legion's thermal imaging radars.

He had to rest. At the very least, he was completely unable to move right now.

His breathing gradually became more even as he adjusted his blood essence fluctuations.

This was a rare moment of peace for him after arriving at the demonic island, and at this point, Tang Wulin could completely understand why this experience had been so traumatizing to Elder Cai and the others. This demonic island really was under the control of demons! Furthermore, according to what Old Demon Nightmare had said, the current situation was different, so it was yet to be seen whether they could make it off the island alive.

Tang Wulin didn't know exactly how much time had passed, but he deduced that he should've been on the island for about three months. During these three months, he'd suffered torture worse than death. If this were the norm for military training, then what was going to await them in the next 21 months?

Tang Wulin heaved a faint sigh as he relaxed his body and slowly recovered his energy. During these past three months, he hadn't even eaten a single bite of food. Even if he could steal another aircraft here, would Old Demon Nightmare be willing to release his friends? It clearly wasn't going to be that easy.

So be it. Whatever happens from now on, all I can do is try and ensure the safety of my friends. As long as I can do that, there's hope.

At the very least, he could use the destructive aura in his body to cross this region of the sea. On this occasion, stealing an aircraft wasn't his sole objective. More importantly, he had to find a way back. If he ever got the chance to rescue his friends, he had to be able to lead them back to the federation.

Tang Wulin had considered requesting assistance from the academy, but he knew that this was not a feasible course of action. He didn't know how the academy would react to his plea for help when they'd been sent here for military training by the academy in the first place, and with Old Demon Nightmare's abilities, he would definitely find out. Tang Wulin didn't dare to take this gamble as the consequences of failure were far too severe for him to handle! He didn't want to see his friends destroying themselves from the inside.

Only after resting for two hours did Tang Wulin's condition gradually begin to improve. This place wasn't the demonic island, after all, and the life force energy wasn't anywhere near as abundant here. As such, after recovering most of his energy, the first feeling that he was struck by was an intense pang of hunger.

If he had known that he'd be this hungry, he would've caught a sea soul beast. Even some sashimi right now would be better than nothing!

He raised his head slightly to look up at the city wall in the distance. Searchlights were scouring the shore atop the fortress-like walls, and night had only just fallen, so he was able to use those lights to see the fearsome weapons that lined those walls.

There was no doubt in Tang Wulin's mind that even if a 100,000-year-old sea soul beast were to try and attack the city, it would be torn to shreds in a short time. The soul technology of the human race had become far too powerful for soul beasts to be able to resist.

It was also due to the rapid advancements in soul technology that Soul Masters weren't as revered as they once were.

There was no way that he could try and cross over the city wall, so what about going underground?

Prior to coming here, Tang Wulin had already devised a plan. He had a pair of powerful golden dragon claws that possessed tearing and crushing special effects, so digging a hole was a simple task for him. However, with the advancement of soul technology, it was most likely the case that there was also defensive and sensory equipment underground as well. If he were to be discovered underground, that could be an even worse situation than if he were to be caught on land.

However, he had to give it a try. At the very least, this was a potentially viable option, whereas directly charging the city wall would simply be completely suicidal.

With that in mind, Tang Wulin slowly released his golden dragon claws to dig the sand beneath him away, thereby allowing his body to sink into the ground.

It had to be said that the Mountain Dragon King's torso bone helped him immensely in this endeavor. He didn't know what caliber this soul bone was, but not only did it give him gravitational control abilities and drastically bolstered his defenses, it also gave him a very high degree of affinity with the earth element.

Tang Wulin's body slowly sank into the ground, and the aura of the Mountain Dragon King torso bone made the earth below him become a lot softer. Through the use of his sharp golden dragon claws, he was able to burrow deep into the ground very quickly.

Oxygen deprivation inevitably became an issue here, but Tang Wulin's immensely powerful physical constitution simply allowed him to ignore that. His Golden Dragon King bloodline circulated through his body, bestowing upon him immense power.

10 minutes later, he had already passed through the sand layer and entered a layer of rocks. After getting to this layer, Tang Wulin began to speed up rather than slow down. This was because rocks couldn't collapse like sand, so he didn't have to use the power of his Mountain Dragon King torso bone to constantly fortify the areas that he burrowed through like he did with sand.

This was not a tunnel that Tang Wulin was planning to use only once; he was hoping that his friends would also be able to escape through it someday, which was why he was very careful in the digging process. Instead of immediately directing the tunnel toward the Northsea Legion base, he was burrowing downward as far as he could. It was undoubtedly the case that the further down he went, the less chance he'd have of being discovered.

An hour passed, and Tang Wulin had already burrowed over 100 meters deep into the ground. During this process, he encountered many problems, such as pockets of underground water. Whenever he encountered such obstacles, he'd have to travel horizontally and only resume burrowing downward after finding a place with no underground water.

This was undoubtedly an arduous and painstaking process, but thankfully, he succeeded in the end.

At this point, he was already very deep underground, the layer of rocks would surely act as an ideal smokescreen for him.

Tang Wulin's breathing was slightly short and sharp at this point. The air here was very thin as very little air could flow into the tunnel from up above. If he were a normal person, he would've perished from asphyxiation long ago, and even with his current physical constitution, he was still beginning to struggle a little.

After roughly ascertaining the location that he was situated at, Tang Wulin began to dig horizontally. In the face of his golden dragon's claws' crushing and tearing special effects, rocks gave away like soft tofu. His powerful arms were definitely more effective than any excavator, and he was quickly traveling toward the Northsea Legion base.

Generally speaking, the military had several types of underground sensory devices, the most important of which were seismographs.

Any changes underground would result in irregular tremors, which would manifest themselves as irregular fluctuations on the seismograph, and that information would be immediately revealed to the people at the legion base. The more powerful the tremors were, the greater the fluctuations on the seismograph. A good seismograph could even detect changes underground from several dozens of kilometers away.

However, seismographs were limited by the fact that they could only detect more severe tremors.

Secondly, there were soul power detection devices that could search for suspicious beings underground by investigating the soul power fluctuations underground. Soul power detection devices could only work in an effective range of around 500 meters underground, but they were far more sensitive than seismographs; any soul power fluctuations that were even slightly stronger than normal would immediately be reported.

These two types of devices coexisted alongside one another to effectively monitor the underground world.

Cases like Tang Wulin's, where no soul excavators or soul power were being used were extremely rare, and even Titled Douluos would struggle to replicate what he was doing, unless they were from the Body Sect. In reality, regardless of how advanced technology was, it was still unable to cater to all possibilities.