You can't make a mistake of this magnitude without having to be put in a water prison to suffer, so the water prison is empty, and there are not even a few guards, because there is no one to guard it.

Because of this, even if Lua brought a human to check the water dungeon, no one stopped her...... It's just that if this matter spreads, I'm afraid it will add another stroke to the unreasonable deeds of the sixth princess.

"You're all outside and you're not allowed to come in without my permission." Luya said to the water prison guard behind her with a cold face, and then she turned her head to look at Su Yu, and did not shy away from the other mermaids who had not yet left: "If Yuzu really wants to build a water prison in her own territory, I can have someone call you the builder of this water prison." ”

Su Yu shook his head slightly, Yu Guang skimmed behind him, and then naturally replied: "No need, I just need to look at it to know how to build it...... But it would be nice if there were drawings available. ”

When Lua heard this, she immediately called out to the mermaids, who had not yet completely left, and asked them to send the drawings of the water dungeon.

"Six Princesses...... This water dungeon is a mermaid tribe's powerhouse, and the blueprint ...... "The mermaid, the person in charge of guarding the water dungeon, spoke hard, trying to dispel this idea from Luya.

It's just that since Luya said so, it is definitely not something that others can convince in a few words.

Luya: "If you want to take it, you can take it, where is all this nonsense?" ”

"Yes." Despite Luya's tough attitude, they finally got the blueprints for the water prison.

"You all go out, don't disturb us to check the water dungeon." After the drawings were in hand, everyone else was kicked out by Luya, and after making sure that there was no one here, Su Yu and Luya began to search according to the drawings of the water prison.

Because this matter is relatively secret, and the two of them are not sure if it is correct, and they are worried that making too much noise will startle the snake, so Lua did not bring anyone, and even she brought Su Yu over, but she also made an excuse.

And this excuse is that Su Yu wants to build a water dungeon in his own territory, so he came over for reference.

Although this excuse is a bit perfunctory, it is enough for unwitting merfolk.

……

The water dungeon is not large, but it still takes a lot of time for only two people to search, after all, there are hundreds of large and small cells here, not including some other rooms.

All the rooms add up, at least three or four hundred, and there is even a floor under this water prison.

But fortunately, the two of them got the drawings, and after they had the drawings, they could explore in different areas, and Su Yu also found out the most likely locations to have problems according to the analysis of the layout of the water dungeon in the drawings.

"Lua, you explore these locations first...... We'll see you here in an hour. "Two people, more than three hundred rooms, an hour will definitely not be able to finish, but there are only a few dozen rooms circled by Su Yu, and an hour is barely enough.

Luya took her own copy of the blueprint, and then went their separate ways with Su Yu.

……

Ten minutes later.

"Huh?" With the map replicated by Su Yu in her hand, Luya came to the location of the fourth marker, and after some inspection, she saw a small hole in the corner of the water prison room.

"It's ...... Well, what a small hole......" Lua came to the corner and crouched down to observe.

As she said, the hole was really small, so small that only one finger could be allowed to stick in, but any more would be at risk of getting stuck.

It's hard for Luya to say whether the existence of this hole is unintentional or deliberate, but she and Su Yu are exploring separately, and the two of them are one left and one right, so she can't contact Su Yu now.

She can only make the next mark on the drawing of the water prison, the location that belongs to this room, and then move on to the next cell......

……

On the other side, Su Yu also encountered a similar situation to Luya, she also saw a few holes in the corners of several of the cells, the difference is that Su Yu has a lot of props on her, and one of them can see the opposite side of the props through this hole.

It's just that there are a lot of holes, and it takes a lot of time for Su Yu to look back and forth alone, and she is also afraid that she will see some strange things and encounter danger, so she didn't do it, but marked the cell with holes on the drawings like Luya.

As she gradually went deeper into the cell, Su Yu inexplicably felt that she was wrapped in a cold air, which made her pores tremble, and at the same time, she also had a trace of retreat in her heart.

As the name suggests, there are many pools in the water prison, plus this is the bottom of the sea, and it is also a place to punish prisoners, so it is stained with a lot of blood, so the yin qi is heavy.

Su Yu used this excuse to convince herself, and then hung a thermostatic rune on her body while continuing to go deep into the water prison.

Five minutes...... Ten minutes...... Twenty minutes......

As time passed, Su Yu suddenly discovered a problem - she seemed to have encountered a situation similar to a ghost hitting the wall!

Of course, the truth is definitely not a ghost hitting the wall, Su Yu prefers that there is a formation here that will make people get lost.

It's just that I don't know where I went, or if I triggered something, how did I walk into this formation unconsciously.

Under normal circumstances, there are only three ways to get out of this formation-

The first is to start from the outside of the formation and directly use violent means to destroy the formation, but obviously Su Yu has already entered the inside of the formation, and she has just tried to try the mermaid blood bead and can't contact Luya, so this method is not feasible.

However, fortunately, the second and third methods were both broken through from within the formation, and Su Yu would not have to sit back and watch.

The second method is to directly attack the formation barrier from the inside by violent means, and the energy of the formation will resist these attacks, and when the energy is exhausted, the formation will be invalid...... But obviously, Su Yu does not have this strength condition.

So the only way she could take was the third way - to find the eye of the formation and destroy it.

It doesn't take much combat power to destroy the formation eye, you just need to take away the corresponding array eye, or clean and apply the formation pattern.

However, this method looks simple, but in fact, it is the most difficult way to crack the formation, because any formation mage with some strength will hide the formation eye to protect the formation from being easily destroyed.

But Su Yu had no choice but to try first.

Thinking of this, Su Yu took out the drawings of the water prison and carefully observed the position where he had marked.

Of course, before doing these things, Su Yu also did one thing, and that was to see if he could use the Huicheng Stone - the use of the button that did not turn gray was the biggest confidence for Su Yu to dare to stay here.