Giant Tunnel

Another day of feeding had passed.

Hunger Hell remained as silent as ever, with its unchanging scorching heat, dryness, and vast expanse of bone sand.

Inside an empty cell roughly two hundred meters from Wang Gao's cell, a thumb-sized hole had been filled with a special yellowish-brown vine.

The more than eight-meter-long small tunnel had not been excavated in a straight line. Instead, it followed weak points within the rock strata to speed up the digging.

Though the straight-line distance was only a little over eight meters, the small tunnel's total length was around 14.7 meters.

At this point, the Drought Algae Vine had already broken through into the Giant Tunnel. The interior of this tunnel was indeed exceptionally spacious, with a radius of eight to ten meters.

Clearly, the tunnel Giant Morley had dug needed to allow him to pass through easily, so its radius could not possibly have been small.

After entering the Giant Tunnel, the Drought Algae Vine swiftly "bore fruit," and more than a dozen "Scout Bugs" flew out from the fruit sacs.

Scout Bee: Similar to a wasp. Possesses night-vision compound eyes, ultra-sensitive Pressure Hormone hearing, pheromone-based smell, environmental camouflage coloring, and radio-wave radar.

Wang Gao devoted part of his attention to directly control the Scout Bees, slowly probing both sides of the Giant Tunnel.

At the same time, the Drought Algae Vine selected its direction and began acid-erosion excavation toward Wang Gao's cell.

Digging from both ends at once would likely cut the construction time in half.

Based on weak sections of the rock strata, Wang Gao also quickly excavated a thumb-wide small tunnel to assist with the digging.

According to the latest revised calculations, the large tunnel was expected to be dug through in eleven days. By then, his main body would be able to enter the Giant Tunnel.

His focus returned to the Scout Bees.

As the Scout Bees continued advancing, the internal structure map of the Giant Tunnel in his mind gradually became more complete and expanded.

As for why he did not directly use Observation Haki to investigate, he wanted to, but Columbus, Magellan, and the others were on the fourth level.

Quite a few people on the levels below the third could use Observation Haki. Sweeping about recklessly with it would easily draw attention.

Wang Gao was a cautious person. There was simply no need to do something so brainless.

Very soon, one Scout Bee sensed intense light ahead. He carefully guided it toward the source.

Once it drew close, he discovered that this place was within the bone sand region of Hunger Hell, specifically amid a Bone Mountain.

The Bone Mountain was where the prisoners' remains were discarded whenever Hunger Hell's cells were cleared out.

The Bone Mountain, more than ten meters thick, was piled high with bones everywhere. The Giant Tunnel's exit in Hunger Hell was hidden deep within one of these Bone Mountains.

The Scout Bee flew more than ten meters through tiny gaps before reaching the interior of the Bone Mountain, where it made a circuit.

After recording the relevant information, he continued controlling the Scout Bee back into the Giant Tunnel and flew onward.

Before long, after passing through a series of sloped paths like a winding mountain road, he heard shrill screams and all kinds of beastly roars. This section of the Giant Tunnel had clearly entered the second level—Beast Hell.

After flying for some time, it finally spotted faint light again. The exit was blocked by an enormous stone, leaving only a finger-width gap.

The Scout Bee cautiously flew through and discovered that this was directly above the Monster Den, the beasts' residential area.

More than ten meters below, a large group of Small Hippos were sleeping in a pool.

After determining the exact location, he controlled the Scout Bee back into the Giant Tunnel once more, followed by another series of Winding Slopes.

Clearly, above this was Crimson Hell on the first underground level. That exit was hidden amid Needle Grass and Sword Tree Forest, with Needle Grass covering the entrance.

It was also located in the rock wall of a Gorge. The Gorge was around three to four meters wide, and Needle Grass grew densely across the bottom and both walls. To enter the Giant Tunnel, one had to pass through the Needle Grass. It probably felt about the same as rolling over a bed of nails.

No wonder so few prisoners entered this place.

Wang Gao discovered that the upward path had not been cut off. Clearly, Giant Morley had once intended to try escaping from the ground level of Impel Down.

The Giant Tunnel leading to the ground level became narrower, and Giant Morley had likely needed to crawl in and out back then.

He found many signs that it had been refilled. This could only mean that after Giant Morley made numerous attempts, he had discovered no way to escape Impel Down from the ground level.

The only remaining passage had an exit on the outer rock wall, more than twenty meters from the sea surface. However, the exit was now blocked by a massive boulder, with only a crack remaining.

Only Scout Bees could pass through. Even a small mouse would likely struggle to squeeze through.

Compared to scouting upward, Wang Gao was even more cautious and slower while scouting the fourth underground level—Scorching Hell, the fifth underground level—Extreme Cold Hell, Level 5.5, and the sixth underground level—Infinite Hell.

This was not merely because he feared those monsters. Another reason was that the Giant Tunnel leading downward became increasingly complicated, like a gigantic underground labyrinth.

He was rather speechless about it. Such an extensive tunnel network had remained hidden for nearly a century without being discovered by Impel Down.

The guards of Impel Down were truly careless. Perhaps this was arrogance—thinking that because it lay beneath the Calm Belt, as long as they guarded the ground-level exit, they had nothing to worry about.

If they had carefully inspected the place with Observation Haki, Impel Down would have found some clues.

Perhaps eight hundred years of being impregnable had made them believe Impel Down was an impenetrable fortress. Unfortunately, they seemed to have forgotten one fact: this world possessed bizarre powers such as Devil Fruits.

The great undersea prison in the Calm Belt appeared to have no other exits, but the seabed itself was an escape route. Giant Morley had excavated a tunnel from the seabed and escaped Impel Down.

After the eight Scout Bees entered the fourth level—Scorching Hell—they encountered an enormous number of branching paths, along with many signs of refilling.

It took the Scout Bees a full five hours to fully survey all the Giant Tunnels in Scorching Hell, as well as the entrances and exits hidden within.

The Scout Bees then began entering the fifth level—Extreme Cold Hell, where the tunnels were once again incomparably complex.

Three Days Later.

The Scout Bees had completely mapped the entire Giant Tunnel, as well as Level 5.5 and the tunnel hidden beneath the sea.

But that Undersea Tunnel was extremely long. Judging by its direction, it had not been dug toward the Grand Line—Paradise, but toward the South Blue.

As for exactly how far Giant Morley had dug, the Scout Bee had already flown through it for seventeen hours. Its cruising speed was thirty kilometers per hour.

In other words, the Undersea Tunnel currently stretched roughly 510 kilometers, and it still had not reached the end.

In truth, that was not exaggerated at all.

The Calm Belt was extremely wide—roughly half as wide as Paradise. Combined, the Calm Belts on both sides of Paradise covered an area about equal to Paradise itself.

If the Calm Belt were not broad enough, it would not have become a nest for Sea Kings. Just thinking about those enormous Sea Kings, which started at several hundred meters long and could reach several thousand or even ten thousand meters, made its vastness obvious.

According to the data in Wang Gao's memories, the Calm Belt between the New World and the West Blue was around 1,300 kilometers wide.

As for the Undersea Tunnel dug by Giant Morley, Wang Gao sent Scout Bees to continue investigating it while putting all his effort into excavating the prison's rock walls. He had already decided to use Level 5.5 as a temporary base.

Thank you all for your support (ω｀)