138: Yellow Sea Sand Cave

Three days later.

At the border of the former Wusu City and Tacheng City.

Before the apocalypse, this place was a vibrant oasis, but after a war in the apocalypse, it became a desolate Gobi Desert.

The Three Mountains was able to discover this place because after being driven away by the Crow, it had nowhere else to go, so it wandered around and luckily found this medium-sized secret realm hidden under the yellow sand.

The scale of a secret realm is not directly related to the difficulty of exploring it.

Instead, it is related to the number of trains restricted for exploring the secret realm.

Small secret realms can accommodate 1-3 trains, medium secret realms can accommodate 2-5 trains, and large secret realms can accommodate 4-10 trains.

When the Xinhuo Train and the Three Mountains arrived, this medium-sized secret realm, the Yellow Sea Sand Cave, had already entered its active period and was in an accessible state.

Vague yellow sand swirled and gathered at the entrance of the secret realm.

It was as if a man-eating giant beast with a wide-open mouth lay below.

"? What is that?"

The Sky-based Early Warning Sphere moved at high altitude with the movement of the Xinhuo Train.

In the monitoring footage transmitted back, there were many strange creatures under the ruins at the entrance of the Yellow Sea Sand Cave secret realm.

They were about two meters tall and four meters long, with body colors ranging from glossy brown to bone-white, and some were purple.

If the fine sand attached to their bodies was removed, they looked like a peeled, muscle-exposed beast zombie.

Especially their disproportionately exaggerated heads, huge lower jaws, and mouths full of sharp teeth.

They picked through the ruins, and when they found suitable materials, they could bite through the rebar under the concrete in one go.

Coupled with their huge, sharp, scythe-like forearms with serrated edges, the collapsed ruins were like a junkyard where they scavenged for materials.

Their compact body structure and developed muscles allowed them to occasionally jump several meters high.

They looked like the Raptors, the basic Zerg unit from StarCraft, a popular game before Lu Yang's transmigration.

Lu Yang observed for a while, and his expression quickly became solemn.

"Liu Lei, when you first discovered the Yellow Sea Sand Cave secret realm, did you find any of these strange creatures?"

On the enemy radar, the weakest of these guys had the energy intensity of a Level 4 mutated creature.

Some elites could even reach Level 5.

Level 4 and 5 mutated creatures were not uncommon in the Intermediate Zone, but this was the entrance to a medium-sized secret realm.

If the peripheral creatures that spread out already had Level 5 strength, how much stronger would the more powerful inner creatures within the secret realm be?

Receiving Lu Yang's real-time call, Liu Lei, several kilometers away, immediately dialed a holographic video call.

"Boss, I saw the photos you just sent."

"When I came last time, there were no such creatures here. And the terrain of the ruins here seems to have changed a lot. Look at the pictures I sent you; the ruins and debris near the entrance of the secret realm have all been cleared out."

Lu Yang compared the photos Liu Lei sent with the current real-time terrain.

Indeed, as Liu Lei said, in the photos, the secret realm entrance was originally a stretch of undulating building ruins, but now, the area near the secret realm entrance has been completely cleared out, looking like a large, concave open space, like a bird's nest, when viewed from afar.

In that open space, there were also ant-nest-like holes, and many 'Raptors' were drilling in and out of the holes.

When they went in, they would be carrying materials like rebar, wood, or zombie corpses in their mouths or on their scythe-like forelimbs.

When they came out, they were empty-handed.

But their body size would have slight changes.

Either their bodies became larger, or their teeth became sharper, or the color of their forelimbs became darker.

It seemed that through the collected materials, they had made a transaction with some entity in the underground secret realm.

Lu Yang parked the Xinhuo Train two kilometers away from the secret realm entrance, waiting for the Three Mountains to approach and rendezvous.

After a while, with the arrival of the Three Mountains, a team invitation followed.

[Level 5 train 'Three Mountains' has sent you a team invitation, inviting you to explore the medium-sized secret realm 'Yellow Sea Sand Cave' together. Do you agree (Yes/No)?]

[Agree!!]

"Team up successful, secret realm exploration begins!!!"

"Secret Realm Pre-task: Please clear out the mutated Zerg 'Raptors' on the outer perimeter of the entrance. Their presence will affect the stability of the secret realm entrance and hinder the entry of trains."

"Pre-task Completion Reward: Green Quality Upgrade Stone x 1."

Lu Yang didn't have any particular feeling about this mission reward.

But Liu Lei on the Three Mountains gasped sharply.

Damn, the pre-task alone offered a Green Quality Upgrade Stone as a reward?

It's just clearing some Level 4 and 5 mutated beasts, is this task that difficult?

At this moment, Lu Yang and Liu Lei's holographic video call had not been disconnected, and with his sensitive spiritual power, he immediately noticed the slight change in Liu Lei's expression.

"What's wrong, Liu Lei? Is there something wrong with this task?"

Liu Lei gave a wry smile: "Boss, the difficulty of exploring this secret realm might be much higher than we previously imagined."

"Do you still remember what I said before, about exploring a large secret realm with the Meteor? At that time, before exploring that large secret realm, there was also a pre-task, and the completion reward was a White Upgrade Stone."

"Our seven or eight trains were caught off guard by the overwhelming mutated white moths in the pre-task. If it weren't for the Meteor's timely intervention, we might have suffered combat casualties before even entering."

"And this time, the reward for our pre-task is a Green Quality Upgrade Stone, which is even more precious than a White Quality Upgrade Stone, so..."

"So the difficulty will also greatly increase?!" Lu Yang interjected.

Liu Lei nodded.

This was the reason he gasped.

He was worried that the difficulty of exploring this medium-sized secret realm would be even harder than the previous large secret realm.

If that were the case, the Xinhuo Train's strength would probably be fine.

But the Three Mountains was not necessarily so.

It might end up being a situation where they didn't get the chicken, but instead made a mess.

Fortune and misfortune are hard to predict!!!