Lukka rubbed his eyes and looked up.

The giant tree not far away that reached the horizon had completely changed its appearance.

On almost every branch that grows horizontally, there are a large number of bright blue spots, like a Christmas tree full of colorful lights. The larger ones, longer in diameter than a normal person's height, and the smaller ones no larger than the size of a fist, shone brightly in the twilight, eclipsing the remaining afterglow of the setting sun.

"This tree is really sick. Phil muttered as he held his hands on the railing of the ship's side.

"I thought the effect you said was just to make the tree turn purple, but I didn't expect so many bright spots. Thea said.

Dolan had already changed back from his vegetative state, and walked to the dock below the ship and asked loudly, "How is it?"

"So, what's wrong with this tree?" Lukka asked.

Phil squinted his eyes for a long time, and shook his head helplessly: "I can't see clearly." Crete, can you help me see if there's a spot of purple light that isn't blue?"

Crete looked up for a moment and said, "There is no such place. ”

Dolan climbed up to the deck from the rope ladder on the side of the ship, looked at it for a while, and asked, "Could it be on the back of the tree?"

Crete shook his head: "No, I can see it on the back, there are no purple glowing dots either, it's all blue." ”

"That's weird. Phil scratched his head.

Dolan thought for a moment and said, "Why don't you go to the tower first and let those wood elves look carefully, maybe that purple point of light is hidden somewhere, and it is not easy to find?"

In fact, in Luca's opinion, there is no need to look for what Crete's eye has confirmed. Staying on the ship wouldn't make any progress, though, and the glittering tree did entice him to get a closer look.

So he nodded and said, "Go and see." ”

Ten minutes later, when everyone walked into the tower, the garrison had already exploded. The wood elves gathered in groups of three or five, discussing what to do with these light spots on the trees.

Garrensel came up and said, "Look at what is the source of the problem?"

Phil walked around the hall, looked carefully from the inside again, and said with a heavy face: "These are not the causes, just the effects." It's just weird. ”

"Is it like this tree is just breaking down little by little, without a fixed source?" said Daniel.

"No!" Phil shook his head firmly, "There must be a cause for effect, and since this potion can trace the result, it is impossible not to have a source." ”

Dolan suddenly said, "I seem to have an idea. ”

He walked to the middle of the hall, looked down and said, "Your potion, which was just sprinkled on the surface, will only be absorbed by the roots of the tree near the surface, and then transported up along the inner conduit and sieve tube, giving the canopy the effect you said. ”

Phil replied, "yes, what's wrong with that?"

"Well, have you ever heard of the saying," said Dolan, "that the canopy of a tree is as big as its root system begins?" ”

"That's right!" Phil patted his head, "I didn't expect that the root system of this tree must be huge, otherwise it would not be possible to support such a tall trunk and branches!"

"You mean, the depth of the tree's underground is as high as the top?" Ollie was a little surprised.

"Not necessarily, only trees growing on fertile soil can have a root-to-shoot ratio of about 1:1, trees growing on land with average soil conditions may have three times as much underground as aboveground, and some plants in deserts can reach 5:1 or more. Phil explained.

"What about the tree?" asked Ollie.

Phil didn't answer, instead turning his head to look at Dolan.

"The sacred tree is not as exaggerated as the desert plants, but this island is not a fertile place with fertile soil, and its root-to-shoot ratio is about 2:1. ”

"That means if it's at the root, then we need to look down there, uh, how tall is this tower?" Lukka asked.

Garantel hurriedly replied: "The place where the garrison is active is sixty-three meters, and there are more than thirty meters above it, which are relatively thin branches. ”

"In other words, we need to probe more than 180 meters underground to find out the cause of this tree?" Luca asked.

"The problem doesn't have to be at the bottom, maybe you don't have to dig so deep. Garrensel said.

"No, you have to start at the bottom. Phil shook his head, "After several of them absorb the water, they are transported through the catheter from the bottom to the top, not the other way around. If you want the agent to reach all the roots, you have to dig to the bottom. ”

Garansel shook his head: "This doesn't sound like an easy task, it's nearly two hundred meters, and even the most experienced miners can't dig it in a day or two." ”

Lukka burst out laughing, "Speaking of digging holes in the ground, we have a crew here with a lot of experience. ”

"You count the rats as crew members?" asked Garrenthal.

"You're a mouse! your whole family is a tree mouse!" said Gavin, the goblin, slamming him on the knee.

Since the goblins could dig a massive city into the ground, it would not be difficult to imagine such a small hole of less than two hundred meters.

However, after Gavin vented his dissatisfaction on the guard's knee, he shook his head at Luca and said, "The excavator didn't bring it, how can I dig it?"

"Don't try to lie to me, you brought so much luggage, there must be tools for digging in it. Lukka almost slipped out, but in fact, he had already asked Crete to check Gavin's luggage remotely several times.

"Okay, okay!" Gavin immediately gave up resisting, "I brought a portable hand excavator, but that thing consumes a lot of energy, and I only have less than four energy crystal nuclei left, if I use it all here, what if I need it in the future?"

"You dig it first, and then I'll give you the crystal nucleus charge. Luca said.

He really wasn't talking big, the crystal nuclei that Gavin was talking about were just some crystals containing magical energy, for Luca, that little energy was pitiful, but when used in the goblin machinery, it could use these energies to the extreme.

Since it's all magical energy, it's not a difficult thing for him to inject some into it, and when he doesn't practice new spells at sea, Luca's magic pool is always full and about to overflow, and it's a waste to put it anyway, and it's not a lot of consumption to charge the crystal with a little energy.

"That's what you said, don't go back! Alright, big ghost, help me get the excavator off the boat. Gavin said.