Steel Steam and Flame

There was a string of lamps in the tunnel, but Cassia did not turn it on. The tunnel nearly three meters wide was flexible enough for Cassia to cope in the dark. The sense of direction has become Cassia’s most sensitive perception at the moment. Her footsteps have been kept in the middle of the tunnel. Every time she deviates from the direction, Cassia will write it down in her head, so that when the detection is completed, she can draw a road map that is not much different from the actual Come.

An air circulation system is connected, and some air delivery pipes are detected by sound pulses. It was not opened at this moment, and the tunnel seemed somewhat dull. If a biological poison is used here, ,, while running, Cassia suddenly thought that mixing into the air, without the enemy's defense, can definitely achieve great results.

No doubt that at the beginning of the construction of the air circulation system, or that other people did not think of this. Didn't say it clearly, maybe he still has a guard against his protectors. The transportation team can be leaked information, and it is still at the top of the organization. It seems that everything can happen if it is driven by interests and today.

The tunnel is almost in a straight line, the angle of the curve is very large, and the sensitivity of perception is slightly lower, perhaps you can't feel the change. And in the middle of the tunnel, Cassia also found a fork in the road. The other route is of course a dead end, which is equipped with many sensing devices, and the sound wave pulse found their outline. When going to the cavity at the bottom of the route, the moving tool like a minecart is more or less prescribed by the analyzer.

I don't know if these forked roads are used to prevent enemies, or to test warehouse management protectors like myself. In the words of Adolf and the departed No. 5, it is easy to guess that such a task is probably a process used to increase the reason and certainty of promotion for some elites. It's like when there is a chance, even if you just handed a cup and other tools, you can still put your name at the end of some important research results.

In less than four minutes, an underground semicircular cavity with an area of ​​nearly a hundred square meters completely revealed its shape, appearing in Cassia's perception. After a few breaths, Cassia, who was standing at the entrance of the cave, made sure that there was no extra detection equipment around before entering the cavity.

With the size of the three-story building, the track in the tunnel was suddenly cut off when it extended to the center of the cavity. There is nothing around except air. On the side, as No. 5 said, several fixed beams of an elevator penetrate the cavity from top to bottom, and two alloy safety doors cut off them, leaving only the space. The cavity is included in the included section.

Cassia walked to the safety gates and looked up and down. Only then did high-frequency sound waves be emitted, penetrating these safety gates and detecting the top and end of the elevator.

“Up to nearly a hundred meters to reach the ground, and down to a depth of nearly two hundred meters, there are three safety doors in between before reaching the bottom end.” Along the elevator shaft, the high-frequency sound beams slowly concentrated in one direction as if they were conscious. "There is an unloading platform at the bottom of the shaft, as well as a simple trolley, which is also a cavity structure. A door connects this cavity, and behind the door are..."

Cassia closed her eyes, and her concentrated spirit seemed to suddenly leave her body, appearing directly under the shaft, and standing in front of the alloy gate. The sound wave frequency suddenly increased by two or three levels at this moment, entering the third stage, and completely self-analyzed the changing structure of the throat. Where is the upper limit of the high frequency sound wave, Cassia has not yet conducted a systematic test at this moment.

As the sound beam moves, the alloy door is like a layer of transparent air, gradually fading in Cassia's head. A wide underground building immediately appeared in front of Cassia. It's just a small part, approximately fishbone-like distribution. In many rooms, most of the equipment and machines for the application are placed. From the weak vibration feedback from them, it can be known that most of the observed machines are operating.

Just without seeing the researchers in the laboratory base for a while, Cassia tried to increase the frequency again, but just in front of her eyes, several glass test tubes placed on the holder broke apart. As if receiving a heavy blow in his head, Cassia immediately stopped detecting and returned to the cavity like a sleepwalking awakened.

Without any words, Cassia lowered his heartbeat and breathing subconsciously, turned and followed the original route to escape into the tunnel. In three and a half minutes, Cassia returned to the basement warehouse again without any change in her face. There was no one around. Upstairs, the other three people were doing their own things in their rooms, and they didn't even know what was happening here at this moment.

Nothing happened, with this mood, Cassia walked back to her room and sat on the bed. After a while, about half an hour, there was no contact sound in the ears or from the communicator, and Cassia exhaled: "I have to find the opportunity and time to study the three stages of the high-frequency sound waves. Changes and applications."

,,,,,,

"Have you brought the record?"

"The assistant is going to print, come here soon." Soon after the reply sounded, there was a knock on the door. After a word of "come in", the door was opened, and a thin man with glasses stood at the door, walking in with three-fingered paper in his hand, and placed it on the table in front of the three people in the room.

"Here are all the monitoring records, all converted into pictures, and recorded once every five seconds~www.ltnovel.com~ I selected the time period within five minutes before and after." There is no tone in the thin man's words. Fluctuation, like a simple and cheap repeater, repeating a boring tone, "I found this in the past, but Professor Mosier."

The thin man said that he pulled out two pieces of printing paper from the bottom of the stack of paper. The warmth had not yet been lost, and the ink seemed to have not dried yet, and its smell spread throughout the room in an instant.

"Several rooms there are shock rooms, and the monitor in each room suddenly showed an ultrasonic record of varying frequencies. Especially the record in the room where the test tube was broken was the highest."

But Professor Mosier said "Oh", took the record sheet from the skinny man, and asked, "In terms of time, the two should overlap completely, right?"

The thin man nodded, "Completely overlap. The machine we used has been checked and there is no malfunction. The record in the analysis machine has also been read. Since yesterday, there has been no record of calling and opening. It is very certain that the test tube is broken. The reason is because a bunch of high-frequency sound waves that came suddenly shattered it, but the source of this sound wave was..."

"I see." But Professor Mosier nodded. "Let's go to the room and take a look."