This beep sounds...... What the hell is going on?!

Qi Lin's first reaction was that there was something wrong with the radio, but after opening the case of the radio and carefully inspecting it, he didn't find any problems.

There aren't any radio stations in the wasteland anymore, and the radio shouldn't be able to pick up any signals, even if it's some messy electromagnetic waves, it shouldn't make such a loud beep!

Qi Lin's gaze stayed on the FM frequency of the radio - FM103.7.

This frequency is not comparable to any radio station in the old era, if it is placed before the war, if the radio is tuned to this channel, it must be a bunch of electric noise heard, but at this moment, the expression on Qi Lin's face has frozen......

The Thunderfalcon team's internal communication channel...... That's exactly 103.7!

Although they don't use this shortwave communication, the channel code is exactly the same.

“…… Is it a coincidence? ”

Qi Lin took a deep breath and plugged in the radio again.

The shrill beep exploded in the room like thunder, and Qi Lin felt the urge to cover his ears, but he still listened to all the beeps.

The more he listened to Qi Lin's face, the more intense the strange color became, and before he knew it, he had accelerated the speed of the Concentrated Energy Vortex to three thousand five hundred revolutions......

After a moment, Qi Lin unplugged the power supply.

To others, it might have been just an unbearable cacophony of noise, but Qi Lin heard something different from this buzzer.

The frequency of the beep is very high, but it is not fixed, it is constantly repeating several frequencies at high speed, and it is completely impossible to hear the change in frequency if you don't listen carefully.

But just listening to the beep is enough to give it a headache, let alone analyzing it with your ears.

Even Qi Lin was able to barely distinguish the change in frequency with the help of the overload force of the shaped vortex.

It's a string of Morse code, and it's repeating three letters of the English alphabet all the time.

“. S”

International distress signals.

Is it Cheng Yanqiu? Cheng Yanqiu's distress signal?

Such an idea popped into Qi Lin's mind, but it was quickly ruled out by him.

The communication distance of shortwave FM is very close, and it is very easy to intercept and decipher, and the members of the Thunderfalcon team will never send a distress signal in this way.

And the most important point - although "SOS" is an international distress signal, the distress signal used by the Thunder Falcon team is another encrypted string of 32-bit characters, and without memorizing the codebook, it is absolutely impossible to read the content contained in this string of characters.

So this distress signal...... Who will send it?

Could it be another dispatch team? But as far as Qi Lin knew, the Thunder Falcon team had not been assigned to missions recently, even those secret missions that would not be archived could be found with Qi Lin's authority after joining the shadow force - at least he could be sure that he was the only member of the organization near the ruins of Leshan City.

And even if it's the other dispatch teams, they don't use the SOS character as a distress signal.

Non-organizational dispatch squads? It would be even more unlikely, even if they were forced to use FM radio to send it, they would not have "bumped" into the Thunderfalcon team's dedicated channel so coincidentally.

"Am I already exposed?"

Qi Lin is the only person around the ruins of Leshan City who knows the special channel of the Thunder Falcon Squad, and it is obvious that the person who asks for help in this distress model is Qi Lin.

Generally speaking, the farthest receiving distance of FM radio is about 150 km to 200 km, and the signal of this beep is so strong, the distance must be a little closer.

Qi Lin opened the map, centered on his location, and drew a circle with a radius of 100 kilometers on the scale, and the source of this unknown distress signal should be within this circle.

As soon as the circle was drawn, Qi Lin couldn't help but furrow.

This circle...... More than three-quarters of the area is within the ruins of Leshan City.

Qi Lin suddenly felt that this distress signal was likely to be a trap.

In an equally classic movie "Alien", the protagonist and others received a "distress signal" from an unknown source, which led to a series of subsequent terrorist incidents.

Could it be a signal from the brain?

But...... If the mastermind has already discovered his traces, why bother to send birth monsters to encircle and suppress himself, or simply wait for himself to go deep into the ruins of the city to launch an attack, anyway, his original purpose is to enter the ruins, why play such a play at this time?

Aren't you afraid that this "distress signal" will have the opposite effect of startling the snake?

Qi Lin believed that with the brain's IQ and computing power, he would never make such a move.

……

Qi Lin tried to change to other frequencies, but it was silent, and only when the frequency was adjusted to FM103.7 could the piercing beep be heard, and the Morse code content hidden in the buzzer had not changed.

"Three points, three long, three points" correspond to the English letters S, O, S.

However, this signal also did not come from the ruins of Leshan City, as for how to determine the direction, Qi Lin thought of a way.

He retrieved a packet of compressed dry food and removed the contents of the food, leaving only the outer bag.

The bags are made of plastic film and aluminum foil, which is known to block electromagnetic signals and is an ideal shielding material.

Qi Lin folded the aluminum foil bag slightly, and then covered the antenna of the radio, leaving only a "window", and then slowly turned the simple "shielding cover" around.

He soon discovered that the signal was strongest when the window of the shield was pointed in the direction of the city ruins, and when it was turned in other directions, the signal was somewhat disturbed.

"Sure enough...... The source of the signal is in the ruins......"

Qi Lin repeated the test twice, and now, he can basically determine that the source of this "distress signal" is in the ruins of the city.

And...... It is the heart of the ruins of the city.

Despite the foreboding in his heart, Qi Lin did not flinch, put the radio back in its place, and he began to continue to move towards the interior of the city's ruins.

From inside a dead city where there was no movement at all, an international distress signal came, which has to be said to be a very strange thing, and this distress signal was still hidden in an extremely harsh buzz...... This seems to be hiding something...... But why cover it up?