As we all know, in 1941, Pearl Harbor of country A was attacked by country J, and the Pacific Fleet suffered heavy losses.

At the beginning of 1943, two submarines of country J ran aground in the western Pacific Ocean and sank one after another. Of course, country A will not give up this excellent opportunity, and sent a submarine to inspect it, and sure enough, there was a major discovery on it, and a large number of top-secret documents were obtained, including the newly used codebook of the navy of country J. The codebook was then sent to the intelligence department of country A for intelligence decipherment.

On April 14, 1943, the intelligence department of Army A deciphered a very important telegram, the detailed itinerary of SB56 was on it, and even what the plane looked like and how many planes there were, Army A would never give up this excellent opportunity to kill SB56, on the 18th, Army A sent 16 P-38 "Lightning" fighters to kill SB56's landline plane and SB56 in one fell swoop. This also illustrates the importance of the codebook.

Li Luant realized the predicament of Wogua, and his voice changed, "Although the decoder is gone, you can find a way to reproduce it." ”

The information communication of various countries in WWWII using radio stations is mainly divided into two parts, one is the transmission part composed of various types of radio stations, and the other is the encrypted part composed of cipher machines and code books. In terms of transmission part, each country is similar, mainly divided into three types of stations: shortwave, medium wave and longwave.

Radio stations rely on radio waves to transmit signals. Radio waves are not lasers, they are not so directive, they rely on diffuse reflection and diffraction, and they can propagate through air and ground. For example, shortwave radio stations have a frequency of 3~30 MHz and a wavelength of 10~100 meters. This wavelength belongs to the meter band, has an obvious diffraction effect, and even forms a ground wave to propagate along the seawater, and the radio station can travel tens of kilometers without a relay. So it's actually a kind of broadcast signal, which can be received by friendly forces, and of course by the enemy.

The radio stations at that time were all analogue stations, unlike today's digital communications. Digital communication must be able to decipher the enemy's dataframe format, which means that you have to use the same baseband module as the enemy to parse their information. Analog signals, on the other hand, can be listened to as long as you tune in to the same band as enemy radio stations. It is precisely for this reason that battlefield regulations require military personnel to use pre-agreed code language when using radio stations, and if they use plain language, it is easy to cause intelligence leakage.

As for the telegram messages, each house has its own key. So if the enemy doesn't have the key, then interception doesn't make much sense.

In order to be able to decipher the messages encrypted by the other side, both the Allies and the Axis powers gathered a large number of mathematicians during WWWII, collected a large number of enemy radio messages to accumulate samples, and then asked mathematicians to reverse decipher. This led to the development of the spear and shield in cryptography.

Now the world's first digital electronic computer put into use was invented by Alan Turing, a genius mathematician in country E, to decipher the Enigma cipher machine in country D. Before the computer was put into use, it was almost impossible to decipher the Enigma cipher machine.

Because of the Enigma machine, the plaintext of the telegram is converted into encrypted messages through the machine.

However, if the telegram is really intercepted by a means, it is necessary to have a "code book" to decipher the contents, and the contents are the Chinese characters corresponding to the numbers, such as intercepting the Japanese characters on the corresponding code book "245, 235, 653, 532, 135" sent by the J Army radio station, which can form a sentence - that is, using Morse code.

Another example is the one that was crushed by Wogua, as long as Wogua didn't crush the codebook, what information has been recorded by this radio station is almost handy.

The radio stations in the WWWII period used radio broadcasting technology, which is equivalent to the current radio signal, and anyone can receive it, but it is just whether the received signal can be decrypted. Because at that time, there were many radio frequencies, and the military's radio frequencies were often changed, so that the other side could not know exactly which one was the enemy's. In addition, there is the telegram encryption technology, although it was intercepted, but there is no codebook, and it is also incomprehensible. The principle is the same as using radio FM to receive broadcast signals, the difference is that the enemy radio signal is received, which needs to be cracked; And to receive the broadcast signal, you don't need to crack it.

The interception of enemy radio stations by WWWII is a technical job, but it is also a boring job. First of all, it is very boring to search for enemy signals but requires very serious work, and the radio frequency is very large, and the difference between the frequencies of the two radio stations is only 0.1MZH, not to mention that military radio stations and spy radio stations are not often turned on. Intelligence personnel must be very patient and wait for the enemy's radio station to turn on, and then they must determine the enemy's radio frequency as soon as possible and quickly and accurately write down the information sent by the enemy.

Receiving information from the enemy radio, to the most difficult step - cracking. Cracking a code is very difficult for us ordinary people, who usually have a codebook, which is only in the hands of the enemy, and the codebook may be a book, and some of them are specially written. The experts who crack the code have their own set of cracking theories, which outsiders do not know.

After cracking the enemy's radio signal, we can reverse write the enemy's codebook, and when the enemy sends a message, we can know the content of the enemy's communication according to the codebook, which is to intercept the enemy's telegram.

The interception of telegrams from enemy radio stations by military radio stations had nothing to do with what radio stations were used, and there were no FM radios at that time. What you need to know to intercept an enemy station is the frequency and call sign of the enemy station. Experienced operators can search for the enemy's common frequency range and determine which station it is based on the method of sending the message, etc. If the judgment is accurate, it can listen to and intercept the other party's telegrams. At that time, anyone could hear the radio station, and they could copy the code, and the sender didn't know about it.

The telegrams sent by the military radio stations were, of course, overclassified. Deciphering a message is a university question. Both countries D and J have suffered from the interception and decipherment of messages. SB56 was ambushed because the message had been deciphered.

Li Luant turned on the power switch, found that it was really out of power, unscrewed two batteries from the flashlight, and then dragged out the coil connected to the power supply in the radio station, and after confirming the positive and negative poles, it was directly connected to the battery, and turned on the switch again, sure enough, this time it could.

Jing Qiongshuang and Wogua couldn't help at this time, and watching Li Luant's operation like a goddess scattering flowers, Wogua couldn't help but ask, "Brother?" Is radio knowledge also one of the compulsory courses in college? ”

Li Luant didn't raise his head: "This is my elective." ”

"Damn, awesome, what kind of university?"

Li Luant smiled silently, just like a truth realized in the English listening test: some words are only said to those who understand.

With the orderly operation of the radio station, there was a sudden sound of "Boom" current, the two listened attentively, and felt that the current sound sounded noisy at first glance, but each transmission seemed to have a certain regularity, and they couldn't help but widen their eyes: Okay?

Li Luant and Wogua and Jing Qiongshuang carefully moved all the accessories of the radio station to the operating table, and Wogua pinched two dry batteries and didn't dare to breathe: For this kind of thing that is now an antique, even blowing on it is blasphemous, and the effect of blowing on it every time is not good, last time I blew on a sleeping beauty, and it turned us like that in that operation room.

A broken heart is like a shard of glass, and the stupidity of love can never be restored.

Li Luant tried a few FMs, and finally settled on a point: nothing else, the traces in this groove were deeper than the others, and most importantly, a layer of yellowish grease formed on it: this is the trace left on the surface of the skin by long-term contact with plastic products, which is longer than the dust in the air.

"Didi-didi-"

The sound is so noisy that it is very difficult to discern it, and it may only be possible to hear one number when it is broadcast for one minute, but fortunately, what the three of them need most now is to find out what is going on here, and this unexpected radio station has become a top priority, so no one complained.

Li Luant broke off a piece of air-dried white powder from the wall, but he could make chalk on the ground, and according to the wavelength obtained by the radio, as long as he could hear clearly, he made a mark.

“23-2，2830，274-，2947，273-，12--，09-0……”

“2730，-284，-273，---1，2837，283-，---9，1---……”

The data is very scattered, and the "-" in the middle indicates the point that has disappeared or been masked, and it is impossible to be sure of course, so this symbol is used instead.

Li Luant wrote from this side of the hospital bed to the end, not that the information he got was vast, but that every piece of information that was played was definitely only said one thing, the problem is that this one thing, every time he listened, he was intermittent, either he heard the beginning clearly, and he didn't hear the end clearly, or he could only get a few short wavelengths, but the other meanings were masked by the noise, and the information obtained was intricate and overlapped, and he could only listen to it a few more times, and then look for commonality in his personality.

This is not a false proposition of a white horse and a non-horse, ignoring the individuality and exaggerating the commonality, which requires finding a subset in a large number of sequences, combining them, and if the remaining data is ignored, then in the subset where each segment is located, find out the most reliable, it seems that the most complete wavelength of the data is preserved.

When the radio indicator flashed red three times, the radio station suddenly fell into a huge noise, as if it was blocked by the jammer from the other side, the loud sound of "bang" exceeded the hertz that the human ear could withstand in a short time, and the nest was closest to the sound source, and he almost became a fool on the spot.

Li Luant covered his ears, tried his best to go to the radio station and turned off the switch, his cheeks were pale and sweaty, Jing Qiongshuang calmed down and watched Li Luant lying on the radio station and gasping for breath, thinking that his condition was very serious, and asked with concern, "What's wrong?" ”

Beads of sweat continued to appear on Li Luant's forehead, fine sweat also appeared on his nose, he gasped violently, and looked up at Jing Qiongshuang apologetically, "We were discovered." ”

In a large pit where the rubble rolled down—

Monsters with black shadows inhabit each other, frantically copulating and mating, writhing bodies exude a strange aura, irritating people's nasal membranes tremble and nausea, and a large pile of mucus flows out of the ground, "ticking" and falling together, forming patches of turbid depressions.

Not far away, there were piles of biological bones, and the freshest of them were four, but these four bones had been gnawed very clean, and the bones were thrown away at random, like garbage.

Beside the four skeletons, there were scattered fragments of camouflage uniforms torn into countless pieces, and some of them seemed to have been swallowed into the stomach and regurgitated because of the fact that the fibers could not be laughed at, so that gastric juice and unknown liquid were stuck to them. In the same color as the rock, there were several guns with polished bullets, scattered on the side, cold and useless, showing not their existence, but a piece of evidence that once controlled their team, and now no longer exists in this world.

The darkness of the underground—

The darkness and loneliness here seem to come from all directions, but the kind of chill that can drive people crazy and surround people's hearts for a long time is the culprit of all this primordial darkness.

Extending forward with the feeling, there is a slight dimness in front of me, as if there is a light smudge, following the line of sight, but in the boundless deep darkness, in a small transparent operation room, there are many sophisticated instruments placed in an orderly manner, but these instruments are not advanced, and can even be called very ancient, it seems to be left over from the WWWII.

Each instrument is spotless, and you can see that there are traces of wiping here, and it is well maintained.

One of the most striking is a main radio station, the indicator light of this radio station is still flashing, it seems that some message has just been sent, so after a short indication of the sign of "message sent successful", it subsided, next to the radio station, there is a box the size of a radio, the box is not very large from the outside, and even at first glance it looks a bit like a video radio built during the Cold War, but the tape in this radio seems to be in operation, with the sound of rewinding.

"Boom, Boom—"

However, the function button at the top of the radio is not a so-called function key, but a red button with four words written in German: "Interference Cell".

The box is still playing a role, but suddenly a hand stretched out from the side, and gently closed the main switch of the box, making a crisp sound of "click", which is particularly silent in this vast uninhabited space.

The hand was bony and covered with green tendons, and the nails were black, and only a cursory judgment was that it should be the joints of a twilight male.

The camera zooms out, the line of sight suddenly extends, and if there is a light shining, you will be surprised to find that not far from the transparent operation room, there are rows of neat black walls, this is not the wall of the weeping God of Jerusalem, nor is it the empty mouth that Mexico is now clamoring to block the two borders, it is real, a whole black wall in operation!!

Each of the walls is marked with a serial number, but instead of a numeric number, it is Japanese characters - "Exhausted", "Not Activated", and "Pending Electricity".

All the black walls have these three different labels, the only difference is that the "Sold Out" label seems to be affixed to a large number, and the "Pending Power" wall has several walls, but the "Not Activated" label leaves only the last black wall.

Looking closely at every part of those walls, it was not any building material, but the bold and incredible conjecture of Li Luant before.

Twelve hours ago—

"Seven years?" "Brother, this guy is estimated to have been reborn twice on Huangquan Road, and so many batteries can only last for seven years in this space?" So why is this light still on? Wogua pointed to the remaining half of the skull's head, incredulous.

Li Luant narrowed his eyes, "So, either we can find ten operating rooms as big as this room, which are also filled with 258 batteries at the same time, or- "Settle down" We are in a strange space that can't even be explained. "Look at the operator, whose face is transparent, lying on the machine" is the same as him, and he can't get out. ”

If there really are ten more operating rooms that are exactly the same as this one, then why the power supply has been going on for decades is understandable, and if not-

Jing Qiongshuang thought carefully for a while, and asked a very constructive question: "What if there is really a battery, but it is hidden and placed in a place where it cannot be seen outside?" ”

The question was indeed a novel and unique question, and Li Luant pondered for a moment, "If these people have a reason why they have to hide the battery—"

This is destined to be unexplained for the time being.

At that time, the conjecture put forward by Li Luant was urgently needed to be solved but not solved, and the question asked by Jing Qiongshuang happened to be stuck in the throat of the most deadly thing that happened in this underground fortress, but he himself did not realize it, and it was precisely because of that problem that it could not be solved that led to a mistake by the next three people, almost paying the price of their lives.

That's right, these black walls are not military instruments, nor are they other great things, they are exactly the remaining 258 large batteries that Li Luant boldly guessed before, and the remaining ten rooms needed.

I've made a big mistake in front of the world,

I have sinned in front of people,

You ought to be their idol,

But they should not be their relatives,

You will meet many admirers,

Compared to the crowd, you are like a shock,

You won't find it among the slaves,

To you, it is an intimate heart.

As long as there is an underclass, I am with it; As long as there is a criminal element, I will go with it; As long as there are geists in prison, I will not be free.

There is only sin and suffering in the world, and even cherries are bitter and sour.

Here, except for the walking corpses that can't open their mouths all over the ground, he is the only one in the past few decades.

It seemed that he hadn't spoken for a long time, and a hoarse voice rippled out in the dark, conveying viciously to every corner, just a simple Japanese sentence.

"Found you, cunning rats."