With Lin Yin's help, Qi Tong almost swept away all the remaining black fish, and then returned to the square to cultivate satisfied.

Without the threat of the black fish, Lin Yin flashed out of the white jade tripod, and surfaced to see what kind of big river this was, which was clearly a drainage hole hewn by man.

Lin Yin didn't feel breathless, which means that the place is well ventilated and connected to the outside. Lin Yin broke through the soil layer and came in, and during the period of sleep, the machine spirit did not sense the exit, so is this exit upstream of Lin Yin's entry or downstream of the current location?

Striking a match and looking at the direction of the flames, Lin Yin took the white jade ding, turned on the flashlight and tied it to his head, and swam downstream.

The waterway is sometimes wide and sometimes narrow, and the narrow parts are all artificially chiseled, and the wide places are mostly naturally formed. This is the practice of changing the direction of the underground river, what is the purpose of this to protect? Lin Yin thought about it and reflexively swam back.

Lin Yin hasn't figured out who he is secretly plotting against in Tianyi Mountain, but Lin Yin is confident that if he is open, he may not lose to the other party, at least if he wants to leave, the other party will not be able to stop him. Even so, Lin Yin still returned to Bai Yuding to meditate and recover every time he advanced, just in case of accidents.

I don't know how much time it took, Lin Yin finally came to the place where he fell asleep, and then the drop in the upper sewer became very large, and the river was turbulent, and he could no longer swim up.

Lin Yin took out a few arrows, sandwiched them between his fingers, and poured true qi into his whole body, his body was close to the waterway, using his hands and feet together, and crawled upstream step by step.

When he came to the place where he fell in, Lin Yin looked up and saw that the hole that Bai Yuding had opened had been closed, but it was a triangular stone instead of a lump of soil that was plugged at the bottom of the hole, Lin Yin was puzzled, but it was certain that the opponent did not chase it down!

After walking more than 100 meters upstream, Lin Yin finally saw the end of the artificial waterway, and at the bend of an underground river, a large hole was dug out, through which all the river water rushed into the hole where Lin Yin came. The old river channel that was intercepted was dry, and there was not a drop of water.

No matter what secrets were hidden here, it was absolutely impossible to leave them without protection, so Lin Yin came to the old river channel and walked slowly along the river wall carefully.

After walking for dozens of meters, a corner of a box was exposed behind a river stone, Lin Yin stood and observed for a while, but did not find anything abnormal.

Lin Yin bent down to pick up a few stones, and threw them in all directions as he went. When I walked up to the box, I saw that except for the eight copper-clad corners, the rest of the box had rotted, and the contents of the box had long since turned to dust.

Lin Yin picked up the corner of the box and continued to walk forward, there were a few more boxes in front of him, Lin Yin stopped, looked around, and then sat down to recover his strength.

I can't see anything wrong, but I always have a feeling of being seduced. Lin Yin thought about the possible threats and countermeasures, stood up, and with a wave of his hand, smashed a copper-clad horn towards the place where the box was. At the same time as the copper ladle cornered the ground, a boulder suddenly fell from the roof of the hole above the box, smashing everything within a dozen meters of the box and its surroundings!

Lin Yin was secretly glad that if he walked over to check the box, he would definitely not be able to avoid that boulder!

Bypassing the boulder and walking forward for dozens of meters, Lin Yin saw a one-person-high hole appear on the side wall of the river, the hole was only two or three meters deep, and there was only one stone step leading to the top.

Standing below, there are a total of forty-nine stone steps, divided into five groups, the bottom group has only nine steps, and the remaining four groups have ten steps each.

Lin Yin thought for a long time, threw the stone in his hand towards the second step, and suddenly the arrows flew wildly, blocking all sides of the steps.

After the mechanism stopped running and everything was calm, Lin Yin threw another stone towards the fifth step, and this time everything was calm, and the mechanism did not react.

Lin Yin picked up a stone again and threw it towards the ninth step, this time the arrows that appeared were relatively sparse, and the gap between the arrows was enough for people to pass through.

After the test, Lin Yin smiled slightly, stepped on the first step, then jumped to the fifth step, and then left foot on the sixth step, flew to the first step of the second group, except for the first group, the rest of each group stepped on the first, second, sixth, and seventh steps in turn.

Ascending the seventh step of the fifth group in one breath, that is, the forty-sixth step, Lin Yin stopped, carefully observed the forty-ninth step, and then jumped up, kicked his right foot on the side of the forty-ninth step, flashed to the left with his strength, and without waiting for his feet to land, his waist twisted, and he turned sideways and landed behind the forty-ninth step.

Lin Yin breathed a long sigh of relief, the level of the person who made the mechanism was too high, the whole body of the arrow was made of fine copper, there was no need to worry about rotting, if the arrow did not hit the target, it would fall to a fixed position, and it would be automatically retracted by the mechanism and used again. The number of steps is forty-nine, take the avenue fifty, Tianyan forty-nine, people escape one of them, that is, there is a lack of heaven, leaving a glimmer of life in people! But Shengyi did not take the first step, but took the ground! The last forty-nine became fifty, and the way of heaven left one, how dare people be full, if they take fifty, they will definitely die. Among them, it is a fusion of life and death, so that Sijiu has become a lore, I don't want to come to Lin Yin, a junior who is both proficient in metaphysics and skilled in a few years!

A few steps forward, another stone staircase led below. This time, there was no more mechanism, and Lin Yin went down the steps smoothly.

There is a stone door in front of him, more than two zhang high and wide, there is a groove on the stone door, it should be a key, seeing this, Lin Yin smiled bitterly and shook his head, such a big stone door can't be opened without a key.

Lin Yin stood in front of the door, thought about all the things he was carrying, and finally decided that there was nothing useful, so he wanted to turn around and leave.

Suddenly, the machine spirit took Qi Tong out of Bai Yuding, and said to Lin Yin with his thoughts: "Check to see if there is a small gap on the door or something, if there is me and Qi Tong, you can go in, although you can't bring anything, but the situation inside the exploration is also good, so make preparations for going in in the future." If there's a mechanism to open the door, then you can go in, and this treasure trove is ours!"

Lin Yin hurriedly walked to the door and began to carefully inspect the various places of the stone gate, once, twice, three times! Lin Yin finally turned around, sighed and said to the machine spirit: "There is no gap between the door of the stone gate, the door frame, and the ground, it seems that all the contact points are just a faint line, if you don't look carefully, you will definitely think that they are a whole!"

Just as Lin Yin sighed and was about to leave, suddenly the white jade tripod shook, and a white gas rushed out of the tripod and rushed directly towards the stone gate!