The core of the treehouse...

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 they invade 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 it down 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 way, Xu Xin's guess that the underground is the main attack is 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 tree 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 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 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 asked. "If possible, I'll infect them 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 great idea!" Wang Lei clapped his hands and laughed, "Haha, with Sister Gui Xin here, dealing with the beasts is so much easier!"

Xu Xin also exchanged glances with Ji Chaoyang, and then they nodded.

"However, we can't let our guard down." Xu Xin said, "This can't solve all the possible situations."

"Yes, the underground passages they dug are likely not interconnected, so it might not be easy to infect a large area," Ji Chaoyang added. "Also, we must be wary of the creatures attacking from underground. They might be very powerful and something 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 hinder the underground digging. If they dig out and enter the ditch, we can also attack from inside. 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 come out of the ditch!"

"Well, at least it can slow down their movements, making it easier for me to infect them." Wen Guixin agreed. "How deep should it be?"

"The cave they dug is five meters deep." Qin Fu said, "Should we 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 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 damage the roots, we need to act from a distance."

But if it is too far, the workload of digging a deep ditch will be too huge.

You need to control 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!"