After entering the cave, it looks much more spacious inside than outside.

Oil lamps are hanging on the walls to make the cave bright.

Five people went in with the leader of the pavilion. The leader of the pavilion said: "in front is the underground palace. There are several tunnels and dozens of secret rooms here. Please don't walk around, or you will easily get lost."

Xu Qing looked around: "no organs, right?"

Cabinet leader: "the tunnel leading to the secret script and the mechanism in the secret room have been closed by us. There is no danger along the way. Don't worry about it."

Walking all the way from the tunnel to the chamber of secrets, Xu Qing saw that three of the disciples of the cabinet leader were also in the chamber, one by one frowning at the chamber of secrets.

The whole room is relatively small, but there is a bookshelf beside the wall, on which are scattered some bamboo slips. There are not many things and they are not messy. It can be said that it is clear at a glance.

In the middle of the stone room, there is a small stone table fixed on the ground. The stone table is inclined 20 degrees, and there is a cylindrical groove in the middle. The pavilion owner said that this is a mechanism, and the groove is used to put secret scripts.

The secret book of Qianji Pavilion is a scroll. It's ten meters long when it's spread out, and it's not light when it's rolled up.

Because of the special weight of the scroll, the predecessors of Qianji Pavilion designed this grooved mechanism. Once the scroll is picked up from the inside, it is bound to touch the mechanism. The mechanism in the stone chamber will also be activated, and the stone gate will be closed, which can basically shoot the enemy into a sieve.

Xu Qing understands why there are so many holes in the wall and ground.

Xu Qing said: "according to the cabinet leader, this mechanism is a weight mechanism. As long as you take away the scroll and replace it with something of the same weight as the scroll, won't the mechanism be activated?"

"But no one knows the weight of the scroll. Even I don't know."

Xu Qing: "what about the predecessor who designed this mechanism?"

"The elder has been dead for 30 years," the cabinet leader said with a smile

Xu Qing: "he may also leave some drawings. How can there be no drawings or records for such a huge organ? Well, even if not, no one came to see the secret script in the meantime? "

Pavilion master: "this secret script contains the painstaking efforts of our Qianji Pavilion. Only I, the two elders in the pavilion and the five disciples under me are qualified to read it. But unless there is something particularly difficult, we will come down to read the secret script only when we have a dispute. Generally, we all read it together, and there is no time to use it alone. "

Xu Qing: "when was the last time I read the secret script?"

Cabinet leader: "six months ago, eight of us came down to see it together."

Xu Qing nodded: "it's also possible that one of the eight of you paid special attention to the weight of the scroll. After all, you are mechanism makers. You should be very sensitive to the size and weight. Some people are gifted. Just weigh them with your hands, you can know how many kilos they have in their hands."

When Xu Qing said this, the pavilion leader and the three disciples could not refute: "yes, after being proficient, we can also check the weight of things in our hands by hand, although it is not absolutely accurate."

Xu Qing: "it's better for us to experiment. Although what I'm talking about is some conjectures, now we have no clue. It's better to experiment every possible situation. Maybe we can find some inspiration from it."

The leader of the pavilion sent his disciples to call the two elders and the other two disciples together to discuss.

Xu Qing asked, "who was the first to come down this morning to check the situation?"

The elder disciple said, "it's me, the second younger martial brother and the third younger martial brother."

The third younger martial brother said: "at that time, we found that someone might have broken into the underground palace, so the master asked us to come down and check whether the secret script was stolen."

Xu Qing: "can you tell us in detail what happened when you came down?"

The gentle three disciples nodded and said, "after my two elder martial brothers and I came down, the stone gate leading to the underground palace in the cave was opened. We came in through the tunnel and found that the mechanism in the tunnel was not touched or damaged. It was still in good condition until we came to the door of the secret room."

"The mechanism of the stone gate of the secret room was destroyed. It was half opened and half closed. At a glance, we saw that the secret script in the middle of the secret room was missing. The whole secret room was full of short arrows and concealed weapons. There was no one in it, and there was no other difference."

"We went in and checked, but nothing was found. The thief left no trace."

Hu Ling pointed to the ground and asked, "what's a little white powder in this corner?"

Cabinet leader: "it's insect powder. We sprinkle this on the floor of the secret room. If someone comes to steal it, we will use flying insects to track the enemy. Insect powder is made of female insects. After being glued, the male can smell it even thousands of miles away, so as to pursue the past. "

"This special smell doesn't go away until seven days later. Unfortunately, in the morning we let the males out, but the males flew directly here. None of them flew to other places."

All kinds of signs make them have no clue. The thieves are so powerful that the people in Qianji Pavilion can't figure out how this man escaped from the hidden weapons in the secret room and escaped intact.

The stone table with the secret script is six meters away from the stone gate. Once the mechanism is pulled, the hidden weapon in the secret room will be launched in a moment, and the stone gate will be sealed immediately.Unless this person can blink, no matter how fast a normal person can get the secret script and escape from the stone gate, it can't be faster than the speed of the concealed weapon.

Xu Qing still guessed: "if you don't want to touch the mechanism, you have to find something to replace the secret script. When he comes out of the secret room, he will take back the replacement, so that the mechanism will not hurt him."

Xu Qing's conjecture is much more reliable than what people think that thieves will do evil.

As for whether the mechanism will be touched when replacing the secret script, we have to test it by ourselves.

"How much is the secret script?" Xu Qing looked at all the people in Qianji Pavilion and said, "you don't have to hide it at this time. You are all mechanism experts. You can easily weigh it and know how many kilos it is. You can estimate the weight of the secret script."

Eight people discussed and reported a number one after another. Everyone's estimates were almost the same. The difference was the number after "two".

However, it's harmless. Even if the design authority's predecessor's accurate weight is too detailed, the weight of the scroll itself will change slightly after being put here for so many years.

After all, it's cloth. There will be an aging process. It's reasonable to say that the weight of the reel will be lighter after many years.

You can't use the mechanism just because it's light.

Therefore, the predecessors of the design department must take this subtle change into consideration and leave room for change.

Because there is no equivalent replacement in hand, the people of Qianji Pavilion can only make a few temporary substitutes.