Because, in his experience of sweeping countless buildings, Lin Cheng knew very well that no matter how well a building's protective measures were taken, it could not avoid the possibility of being penetrated by the nibbles and those desperate survivors, not to mention that the location of this research institute was in the most prosperous area of Yanjing, how could such a place that seemed both conspicuous and safe not have a survivor to fight it?

Thinking of this, Lin Cheng did not rush to continue walking upstairs, but turned around and returned to the main entrance, seeing that Lin Cheng was back, Lin Yongjian was about to ask, but saw Lin Cheng waved his hand and signaled for a while.

Returning to the glass door that he had just entered, Lin Cheng squatted down and picked up the door lock that had been stabbed by him with a sword, and after careful observation, he suddenly found that the design of this door lock was much more complicated than he imagined!

According to the complexity of the design of this door lock, it is impossible for ordinary people to break it by violent means, and the biggest reason why he can enter it so easily is because his long sword is too sharp.

Finding that even the design of a pair of door locks was so complicated, Lin Cheng couldn't help but raise his eyebrows, and then checked the glass door non-stop, and found that it was indeed as he speculated, this door that looked no different from an ordinary glass door turned out to be bulletproof!

After checking this, Lin Cheng didn't go any further to look elsewhere, because even if he didn't look at it, he knew that all the windows of this building should be made of bulletproof and explosion-proof glass, and there should be a protective net outside.

This impregnable defensive measure made Lin Cheng's mood more and more excited, the more strange the situation in this research institute, the more unfathomable the water in this place became!

After thinking about it, Lin Cheng stood up, raised his left hand, and directly summoned a piece of frost to seal the door, eliminating the possibility that he was secretly infiltrated and disturbed by other survivors in the search institute, and after beckoning to Lin Yongjian, signaling him to follow him closely, and slowly walked towards the second floor.

Under the search of Lin Cheng and Cola, it has been basically determined that the first floor is only used for the office of clerks and has no other role, so Lin Cheng will not continue to grind on the first floor, and go directly to the second floor.

"That...... How do I feel weird here? ”

After going up to the second floor, Lin Yongjian glanced at the empty corridor in front of him, and asked Lin Cheng with some trepidation.

Although the strength is not strong, after all, Lin Yongjian is an old fritter who has been crawling around for a long time in the last days, and he has also entered a lot of places when collecting materials, but the situation of this research institute is different from all the buildings he has seen, the thick dust on the ground means that no one has ever been to this place, and the door downstairs seems to have never been opened, and the whole research institute is like a forgotten by everyone and monsters, which makes him suddenly feel a strong uneasiness!

Frowning and sensing the situation on the second floor with his six senses, after hearing Lin Yongjian's words, Lin Cheng nodded slightly, and said, "Your feeling is normal, this place is indeed different from other places......

As he spoke, he saw a door appear on the left, and walked in directly with the doorknob.

After entering it, the first thing that caught Lin Cheng's eyes was three rows of long test benches, on which were placed all kinds of strange-looking experimental equipment, which were all covered with dust at this time, and the whole laboratory looked like no one had used it for hundreds of years.

The surrounding walls then looked fine at first glance, but under Lin Cheng's careful observation, he still found something strange.

Walking to the wall on the right, Lin Cheng squinted for a moment, then suddenly stretched out his right hand and pulled out an iron nail from it with a "bang"!

After taking a few careful glances at the iron nail in his hand, Lin Cheng couldn't help but sneer, and raised his head towards Lin Yongjian, who had an unknown face behind him, and asked, "Look what this is?" ”

Hearing this, Lin Yongjian hurriedly glanced at it and found that it was just an ordinary iron nail, and his expression became even more confused, "No...... Isn't it just an iron nail? ”

"Stupid!"

Seeing that this thing hadn't reacted yet, Lin Cheng couldn't help but scold him, and then stretched out his hand and pointed to the wall and said to him: "You count me carefully, how many iron nails are on this wall!" ”

Hearing Lin Cheng's angry rebuke of hating iron and steel, Lin Yongjian also felt very embarrassed, but he was uncomfortable from the moment he came here, how could he still have the heart to observe other details?

Following Lin Cheng's gesture and hurriedly walked to the wall, Lin Yongjian looked up and looked at it, and suddenly "chuckled" in his heart, and finally understood why Lin Cheng cared so much about that iron nail!