The sound of Xu Xin's watch was played out loud, so Ma Hongwei and Zeng Tao could hear it.
Both of them were surprised and turned to look at Xu Xin's watch.
"Underground? Digging a hole underground?" Zeng Tao exclaimed.
“Underground…” Ma Hongwei frowned immediately.
The sky and the earth are fine, but underground...
His abilities didn't seem to be able to handle the situation.
Xu Xin thought a lot in an instant.
Coming in from underground... I should have considered this possibility earlier!
Although there is a safe zone around the tree house, the roots will protect the surrounding land from damage, but…
That might only be useful against low-level wild mutant animals and plants!
At this time, the World Tree has not yet fully grown, and its roots are at their most vulnerable.
Could it be that... the other party wants to destroy the roots of the World Tree? !
No... probably not.
The root system of the World Tree is very wide, and its affected area can even cover the entire 188th area, which they cannot destroy at all.
Therefore, they should want to destroy the body of the World Tree!
"Yes, it came in from underground!"
Qin Fu was a little out of breath, obviously running: "Just to the east of Crystal City, I found a cave that was dug underground. The depth is about five meters underground. This cave has penetrated about five or six hundred meters into Crystal City!"
A cave about five meters underground and five to six hundred meters long!
Only caves
"Is it just a cave?" Xu Xin asked immediately, "Are there no wild beasts or mutant creatures?"
"When I excavated it, it was gone." Qin Fu responded, "There is only one cave left, which is about... less than one meter in diameter. It is very narrow. If people want to enter, they will probably have to crawl. The creature that dug the cave should not be very big."
"Where is the location?" Xu Xin asked again.
"It's just a few meters outside the Crystal City, but the entrance to the cave is completely flat and has been filled up. There's no trace of it at all."
The entrance is just outside the Crystal City...
All the trees near Crystal City have disappeared. If it weren’t for this tree planting, Qin Fu might not have noticed it at all.
"According to my observation, this cave was definitely just dug. Judging from the traces in the soil, the guy who dug the cave probably left not long ago."
"So...last night?"
"No, this morning!" Qin Fu asserted, "This cave was definitely newly dug this morning!"
“… But, I don’t know who dug it.” Xu Xin thought of something and his face turned a little ugly.
"Yes." Qin Fu seemed to stop, took a breath, and sighed, "Another one."
"Another underground cave was discovered?" Xu Xin's eyes narrowed. "Where are the mutants? Are there any mutants digging?"
"No, there is only one long hole, and this one is even longer, with..."
Qin Fu ran again. After running for more than ten seconds, he stopped and panted slightly, saying, "About seven or eight hundred meters!"
Seven or eight hundred meters...
The radius of Crystal City is only about 2.5 kilometers, and seven or eight hundred meters is considered a relatively deep position in Crystal City!
"Looking at it this way, there's no need to worry too much." At this time, Zeng Tao on the side said, "They only dug a few hundred meters and left. This means they can't stand it anymore. If they can stand it, shouldn't they dig directly to the innermost part and destroy the World Tree?"
"No." Xu Xin directly denied her statement, "Seven or eight hundred meters is already very deep. If it would be affected, it should have been affected long ago."
If we can reach a position of 700 to 800 meters, we will definitely be able to go deeper and directly enter the center of Crystal City and reach the location of the World Tree.
"Hmm? Then what do you think happened? Why did they turn back halfway through digging?" Zeng Tao asked in confusion, "Give up halfway?"
"Another one has been found." At this time, Qin Fu's voice came from the watch again, "This should be the last one. This one is about five or six hundred meters long."
"See?" Zeng Tao was a little proud. "They all stopped at this distance. Doesn't that mean they can't get in any further? That must be the case."
Xu Xin glanced out the window.
What Zeng Tao said is not without reason, but...
At this time, Ma Hongwei, who was sitting in front of his test bench, put down the blueprint in his hand and said, "If there are only three caves, could it be just a test?"
"Probing?" Zeng Tao turned back to look at Ma Hongwei, "What do you mean?"
"I had the same idea." Xu Xin nodded slightly, "This is obviously a test. If you want to attack the World Tree... what's the use of just a few narrow passages like this
These passages may just be a test for the other party to see if they can dig a hole underground to enter the Crystal City and get closer to the World Tree."
"That's what I think."
On the other end of the voice, Qin Fu spoke again.
"Why do you all think so?" Zeng Tao curled her lips.
"After going several hundred meters deep, the spies determined that they could approach the World Tree from underground, so they left." Xu Xin explained the situation to the group of explorers.
As for why they went back after reaching a distance of seven or eight hundred meters, Xu Xin believed that the closer to the body of the World Tree, the more developed and dense the root system of the World Tree should be, and the difficulty of excavation would increase exponentially.
"We need more diggers." Xu Xin narrowed his eyes and looked out the window. "So, they are going back to ask for more troops."
"Ah?" Zeng Tao immediately ran to the window and looked out. "You mean... a large army is about to attack?"
“It’s possible.”
Everyone in the explorer group saw the message sent by Xu Xin.
Wang Lei: "Fuck, are they sending a big rat over here?"
Zhao Xiaochuan: "Digging a hole underground... I thought the ground was the safest place with the World Tree and the tree house root system protecting it..."
Qin Yunlong: "What if we really dig this out from underground?"
Ji Chaoyang: "Let's gather under the World Tree to discuss."
Qi Xuefei: "Okay."
Wen Guixin: "Wait for me, I'll go back right away, I'm a little far away! I'm on the periphery watching these mutant creatures that have surrendered!"
Xu Xin also wanted to leave immediately.
"I want to go too!" Zeng Tao immediately wanted to follow Xu Xin.
She wanted to escape from here.
"I won't go." Ma Hongwei waved his hand. "I can only be responsible for the guys above the ground and in the air. I can't handle the guys digging holes underground. I might as well do more research."
Xu Xin nodded.
He doesn't like crowds in the first place, and generally won't join in unless it's necessary.
"Let's go."
Xu Xin and Zeng Tao got down from the tree house and came to the side of the World Tree.
Looking at the World Tree again, it is still growing, but not as fast as before that can be seen by the naked eye. It cannot be seen without careful observation.
Except for Wen Guixin, who was a little far away, and the person involved, Qin Fu, everyone else had arrived.
Even Lou Feier and Jin Yue were there.
After all, Lou Feier is also in the group and can see Xu Xin's news.
At this time, Jin Yue had completely changed.
The figure is more upright and the skin is so tender.
Seeing Xu Xin looking at her, she nodded slightly, indicating that she had fully recovered.
At this time, Qin Fu came back.
He walked directly towards the place where the crowd gathered under the World Tree.
Wen Guixin followed closely behind.
"Qin Fu, tell me again clearly what you found out."
"Okay." Qin Fu nodded, "It's like this..."
Qin Fu described the situation in the cave in detail again.
"We really need to think seriously about countermeasures." Ji Chaoyang said in a deep voice, "It's not easy to stop the underground invasion."
"Drilling a hole underground..." Wang Lei stepped on the ground. "These alien invaders really use all kinds of despicable means. Are they trying to steal a house directly from underground?"
"Are they going back to call the army?" Zhao Xiaochuan said worriedly, "Doesn't that mean they will be here soon? We must think of a solution as soon as possible!"
"No." Xu Xin expressed his thoughts, "Maybe, not that fast."
Everyone else looked at him.
"My idea is that it's not that easy to conduct an underground invasion in secret," Xu Xin explained. "After all, if there are too many mutant creatures digging holes underground, it would be easy for us to discover their movements. Especially for me."
Xu Xin has map-building abilities, and how could he not notice large red dots appearing around him
"That's right." Ji Chaoyang also agreed, "Moreover, there are still a large number of mutant creatures who have surrendered to us at the edge of our Crystal City. They may not take any action if there are only one or two of them, but if the enemy appears on a large scale, they will not remain indifferent. If we want to launch a large-scale attack, it is impossible not to be exposed."
"That's true." Wen Guixin nodded. "I went to see the group of mutant creatures. They are now full of energy and very friendly to me. They also expressed their desire to protect Crystal City."
"What if it comes from somewhere farther away?" Qi Xuefei asked.
"That is indeed a possibility." Xu Xin took over and said, "However, what I want to talk about is another possibility. That is... the underground army may appear together with the ground and air armies."
Xu Xin's words made everyone present change their expressions slightly.
"If it were me, I would do this. When a large number of mutant creatures appear together, some of them will burrow into the ground and will not be conspicuous.
These mutant creatures are heading towards the World Tree from underground, while the enemies on the ground and in the air are responsible for attracting their attention. "
"We have prepared many methods to deal with ground and air enemies. We have the tree house heavy crossbows, which have good anti-air capabilities. Combined with Sister Gui Xin's abilities, the beast group is nothing to be afraid of."
"But..." Xu Xin pointed to the ground and said, "While we were happy about repelling the enemies in the air and on the ground... the enemies underground might have destroyed the World Tree. If it weren't for Qin Fu's ability, this might have been what happened to us."
Xu Xin's words silenced everyone around him.
Everyone, including Xu Xin himself, felt a chill.
That's true.
If Qin Fu didn't have the ability, and if the opponent really arranged it this way, then they might really have been attacked without knowing it.
"It's very likely." Ji Chaoyang looked at the World Tree beside him, "Moreover, digging a hole from underground to under the World Tree may be able to better destroy the World Tree. Underground attack may really be their real means."
"Why?" Wang Lei was puzzled. "The root system of the World Tree is so developed. It won't do any good if they destroy a few of them. They still need to destroy them severely. It's better to dig the ground."
"First, there is a crystal city up there. It's not easy for them to get in." Ji Chaoyang patted the World Tree, "Second, this World Tree is also a tree house, so it should... also have a tree house core."
The tree house core…
Yes.
Everyone reacted immediately.
Where is the core of the tree house
Half buried in the soil beneath the hollow of the tree trunk.
If it invades from underground...
Maybe we can just dig out the core of the World Tree’s tree house!
In that case, there is no need to destroy the World Tree. Without the core of the tree house, the World Tree will naturally wither and die.
They were all very familiar with what would happen to a tree house if it lost its core.
However, it would be very difficult to destroy the World Tree from the ground.
Simply causing some damage will not destroy the tree house. If you want to destroy the tree house from the ground, you need to cut the tree house directly.
But the World Tree is so thick...
Xu Xin looked at the World Tree again.
Now the diameter of the trunk of this World Tree is probably more than ten meters.
An extremely thick and tall towering tree!
It seems impossible to break this tree on the ground.
In this light, Xu Xin's conjecture that the underground was the main attack was becoming more and more reasonable.
but…
Xu Xin looked at the World Tree again.
Isn't this world tree a little... too thick
The world tree in Shi Wanyun’s memory is about this thick, right
And this world tree seems to need a few more days to grow.
Is this tree stronger than the world trees of those alien invaders
… When Yingying was here, I should have asked more questions about this world tree.
All he knew now was that this world tree was the most successful tree house seed in their experiment.
"Now that we know, how do we solve it?" Wang Lei pointed to the ground. "It seems that we don't have any way to deal with the mutant creatures that burrow underground, right?"
Indeed not.
Everyone frowned, thinking about how they should respond if Xu Xin's guess came true.
At this time, Lou Feier tugged at Xu Xin's clothes and whispered, "Can't your pangolins also dig holes? I went to take a look this morning, and the two little ones have grown quite big. Can they be put to use?"
Pangolin's beloved concubine and those two little guys
yes!
My beloved, you should have been promoted to a mid-level mutant creature by now!
"Xu Xin, can your pangolin pull out a few burrowing mice from the ground?" Wen Guixin said, "If possible, I will infect the guys I pulled out and then let them burrow back in..."
Hearing this, the eyes of the people around lit up.
Let that infected guy infect the entire underground legion!
Let them all die in the ground!
"What a good idea!" Wang Lei clapped his hands and laughed, "Haha, with Sister Gui Xin here, it's so easy to deal with the beasts!"
Xu Xin also looked at Ji Chaoyang, and then nodded.
"However, we can't just let our guard down." Xu Xin said, "This can't solve all the possibilities."
"Yes, the underground passages they dug are likely not interconnected, so it may not be easy to infect a large area." Ji Chaoyang also said, "Also, we must be wary of the very powerful creatures that may appear among the underground attacking creatures, which Wen Guixin cannot infect in a short time."
"Then we should..."
"Dig a ditch." At this time, Qi Xuefei proposed a plan, "Dig a deep and wide ditch around the World Tree. This way, we may be able to stop the underground digging. If they dig out and enter the ditch, we can also attack them. The tree house heavy crossbow can also come in handy."
“That’s a good idea!”
“That makes sense!”
“If you dig deep enough, they’ll have to be dug out of the ditch!”
"Well, at least it can slow down their movements and make it easier for me to infect them." Wen Guixin also agreed, "How deep should it be?"
"The cave they dug is five meters deep." Qin Fu said at this time, "We should dig ten meters? Fifteen meters?"
"So deep..."
Ten meters is the height of a three-story building.
Fortunately, they have advanced tools, so digging is easy.
There are also three pangolins with super fast digging speed.
"Well, we can give it a try." Xu Xin thought for a moment and said, "However, the roots around the World Tree are probably very close to the ground. If we don't want to destroy the roots of the World Tree, we need to do it from a farther distance."
But if it is too far, the workload of digging a deep ditch will be too huge.
You need to determine this distance yourself.
"In that case, let's act quickly!" Zhao Xiaochuan took out a shovel, "I don't want the core of the World Tree to be dug out!"