Ma Xiao still suppressed his impulse, helped Li Mu clear the mines, and then continued to move forward. At nightfall, we came to the edge of the city.

All cities have walls, and Nanhu City is no exception. And since the rebels had no relationship of resistance, the wall was quite well preserved. There won't be guards everywhere, but it's no easier to sneak past the tall wall and into the city than through the jungle.

"It's going to be a bit of a hassle here. Ma Xiao looked at the team members: "The main function of the wall is to resist dangerous species, not only strong and heavy, but also an alarm protection system. So we can't climb through it, we can only go through the secret door in the wall. The secret door is designed to protect humanity, and we only need to activate the wall's escape system to get in......"

The wall is a line of defense to protect the city, but it also has hidden dangers. As soon as there is any danger in the city, this wall becomes the biggest obstacle. Although this is not very likely, it cannot be ignored when it is built. Therefore, the separation wall of any city has many secret doors.

The secret door is secret, and ordinary civilians and even ordinary officials will not know about it. But for the students of the First Military Academy, this can only be regarded as common sense. So everyone doesn't quite understand why Ma Xiao would talk about this with a serious face.

When Ma Xiao was popularizing science, Li Mu didn't listen to it, but ran under the separation wall and touched it curiously.

As an important defense facility of the city, it is strictly forbidden for idle people to approach on weekdays, and even visits are not allowed. Especially from the outside, few people can see it, and it is the first time for Li Mu to observe it up close.

was groping, Li Mu sighed.

How can there be a lock here?

The wall that you touch looks smooth and flat, no different from the rest. But Li Mu almost instantly determined that there was a lock here.

During the few months in the psychiatric hospital, in order to lock Li Mu up, the hospital changed almost all the locks that could be used. Thanks to that experience, as long as it is a lock on the thundercloud star, whether it is high-level or low-level, there is basically no one that Li Mu does not know.

Li Mu knew that there was a secret door in the separation wall, and he was also trying to see if he could find it. But there will be no lock on the secret door, which is obviously installed by someone.

The wall has a security code, and the permission to modify it is in the Planetary Administration. No matter how long the rebels occupy South Lake, they will not be able to change the security code unless the wall is torn down and rebuilt.

Li Mu pondered, the rebels have occupied Nanhai City for a long time, although they can't get federal authority to change the security code of the wall, but it won't be too difficult to do some damage. For example, on the basis of the secret door, some secret passages can be rebuilt, from which you can enter and exit or hide, and sneak attack the federal army.

The federal army may not be unaware of the existence of these secret doors, and must have conducted a large-scale investigation. It's just that there are too many of them, and it is inevitable that there will be misses.

The one that has been discovered now is very hidden, with extremely sophisticated hidden locks. But as a master of lockpicking who came out of a mental hospital, how could he be difficult.

The source energy body of the dark lock was not nearby, and Li Mu had no way to copy it. However, there are many ways to pick locks, and they don't all have to rely on the second barrier.

Li Mu took out a small tool kit, injected the source energy into the dark lock, and tinkered with it on the wall.

When Li Mu was contemplating the lock, the students and Ma Xiao were still communicating about the secret door.

"Captain, the escape system is on the inside, and it's basically impossible to open on the outside. ”

"It's hard to open, but there's a way. Ma Xiao said: "I have the security code of all the walls in the new third area, and I can control it from the outside. ”

The students were shocked.

The security code of the wall is considered the city's top secret, and is usually known only to the mayor and the commander of the garrison. But their senior actually has the ability to get all the security codes in the three districts.

"However, even if there is a security code, it doesn't mean that the escape system can be activated...... right" Guo Peng thought for a while: "If I remember correctly, the activation of the escape system requires a lot of authorization, and a single security code can't do it." ”

"That's right. Ma Xiao said: "But the core principle of the escape system is to protect human beings, as long as the system determines that human beings are in danger, it can be activated without authorization." And we're not starting the whole system, we're just opening one of the secret doors. ”

"How?" someone asked.

"Let the system determine that human life is at risk. Ma Xiao emphasized this sentence with heavy words, and looked around at everyone: "The method is a bit complicated, so I won't go into detail with you." To put it simply, I need a victim. ”

The students who were eager to try it before were like being splashed with cold water on their heads, and they were all stunned.

"What, didn't you have the consciousness of sacrifice before you came?" Ma Xiao smiled: "Haven't you been quite unconvinced along the way." How is it that when there is a need, no one can stand up?"

"Senior, we are not afraid of death. Guo Peng's face turned red: "It's just that I haven't even seen the shadow of the enemy, so I have to die inexplicably, it's really a bit ......."

"There are many kinds of sacrifices, and not all of them will die at the hands of the enemy. Ma Xiao sighed: "You are too naïve, which is why I am unwilling to take you on a mission." If it were an experienced veteran, why would I have to explain so much. Just give an order, and someone will do it......"

"I'm coming!"

"No, I'm coming!"

"And my ......"

Feeling insulted, the cadets stood up one by one.

Because it was so close to the city, no one shouted out loud. But the flushed faces and the fists that were waving vigorously confirmed the excitement of the students.

As Guo Peng said, this way makes them not very willing, but no one will be afraid of death.

Just when the students were impassioned, Li Mu made a breakthrough.

With a click, it seemed as if something had been opened inside the wall, and a small piece slowly rose. Li Mu groped around the edge, grabbed a buckle, and with a little force, a secret door was opened by Li Mu.

Ma Xiao turned his back to the wall and didn't see this scene, but the students saw it really.

At first, everyone didn't care what the deputy captain was doing, but a black doorway suddenly appeared on the wall, how could they not notice.

The students' voices froze and their voices became hoarse.

"What's the matter? can your courage only last so long?" Ma Xiao laughed mockingly.

"Captain, there......" Guo Peng stretched out his hand and pointed.

Ma Xiao frowned, looked back, and just saw Li Mu getting into the wall, leaving only a big ass to twist outside.

"This seems to be able to go inside...... Li Muchong waved his hand outside: "Who has a flashlight or something, use it, it's too dark......"

The corners of Ma Xiao's eyes twitched vigorously, and the students' faces were even more exciting.

"Captain. Guo Peng looked at Ma Xiao: "Didn't you just say that it takes a person to open the secret door?"

"We need an explanation. ”

"Yes, Captain, you speak......"

Facing the questioning and even dissatisfied eyes of Guo Peng and the students, looking at Li Mu's ass, Ma Xiao didn't want to say anything.

There is only one sentence to say.

MMP, it's not scientific.