"Brother Captain, the investigation of the surface ruins of that undersea city has been completed." With special attention, the investigation progressed particularly quickly. Only seven days after everyone discussed, Zhou Xin heard the news from Atlas's mouth.

"What are the results of the survey in the last area?" Zhou Xin asked expressionlessly, after hearing the news, he didn't feel happy at all. In the past few days, he has to listen to the day's investigation report every night, but each time he gets the same information. Now, as he said, there is only one last area left, although Zhou Xin still has a faint hope in his heart at this time, judging from the expression of the little girl on the screen, he seems to have the answer to his question.

Sure enough, Atlas gave the same answer as the previous day with a slightly disappointed tone: "Aside from the ruins of the building and a large amount of household waste, the probe did not find any valuable targets. ”

"It seems that I can't give much hope." Sighing slightly, Zhou Xin said to himself, "In the end, I have to drill into the undersea rock formation to see." Atlas, is the probe ready? ”

"Hmm." The little girl nodded, "We've already started to get the probe ready to go deep into the rock formations from the area where it was last investigated." After a few days of consideration, they are going to conduct two rounds of surveys of the rock formations on the seabed, the first of which is a rough scan of the rock formations in the area where the ruins of the entire town are located with scanning equipment to see if there are large cavities hidden in the rock formations. This round of inspections does not take much time and is expected to be completed in about five days. However, under the influence of the complex environment of the seabed mentioned earlier, the accuracy of this round of scanning should not be very high, and it is easy to ignore those smaller cavities. Therefore, a second round of accurate scans is required, but accurate scans are quite time-consuming, and even people have no way to estimate how much time this round of inspection will take. ”

"What is the approximate accuracy of the first scan?" Zhou Xin asked, "If the accuracy is high enough, we don't need to conduct a second round of inspection."

Atlas replied with a wry smile, "Judging from the test results of the first scan, I'm afraid that the first round of detection can only find holes that are more than five meters long, wide and high. And this is probably still in a relatively ideal situation, depending on the material of the rock layer, the final detection results may be less accurate. ”

"More than five meters?" Listening to the little girl's answer, Zhou Xin looked a little disappointed, "Let's not talk about whether the height of the control center will exceed five meters, just a space with a length, width and height of five meters, with our technology, it is enough to hide a small control center." However, now in addition to the method proposed by Atlas, Zhou Xin can't think of a better way for the time being, so he had to order, "Let's investigate according to this method first, and then talk about it later when we can think of a better way." After saying this, he couldn't help but show a worried look on his face.

As if seeing Zhou's thoughts, Spred opened his mouth and comforted, "Fortunately, in the past two days, it seems that the frequency and scale of the other party's attacks have not continued to expand, but seem to be showing signs of convergence. If we continue like this, maybe we will be able to hold out until we find the control center. What's more, until now, our mining area has not been attacked by the other side. ”

"It's not certain, maybe it's a precursor to a larger operation." Dart, apparently not as optimistic as Spreed, spoke his mind.

"Anyway, we have to find the control center as soon as possible, otherwise the overall situation will be quite unfavorable for us." Obviously, at this time, Zhou Xin's idea was more similar to Dart's.

Soon, just five days passed. In the end, the results of the first round of scans disappointed Zhou Xin, and there were no signs of any large cavities in the rock formations below the town. Even after this round of scanning, Atlas came up with an even worse result.

"Brother Captain, I'm afraid we won't need to do a second scan of that area in the future." While everyone was still basking in the frustration of finding nothing, Atlas hesitated, but still stated the results of his analysis.

"Why?" Disappointed, Zhou Xin was not happy that he could save a lot of effort in the future, and he immediately asked rhetorically, "Didn't you tell me that the first round of scanning couldn't find those small cavities?" ”

The little girl elaborated: "During the first round of scanning, it was found that most of the geological structure under the ruins was not a hard rock formation, but a layer of sand and gravel that was very thick, loose and prone to collapse. Although it is not certain whether the gravel layer existed at the beginning of the town's construction or after it sank to the seabed, it is certain that it is difficult to have stable cavities in such a geological formation. Even if the original continental civilization had the ability to expand a certain amount of space underground, under the water pressure at this depth, those spaces—" She didn't continue, just shook her head silently.

"In other words, the control center can't be under that ruin, right?" Spred still reluctantly confirmed.

"Now, unless that civilization has some unique technology that people don't know about, it's very unlikely." Atlas spoke the brutal truth. Then she added in a hopeless tone, "However, for some of the areas that may have been voided in the first round of scans, people will still take some time to investigate in detail." ”

After the little girl finished speaking, everyone in the command cabin, including Zhou Xin, fell into silence, and after a long time, Dart said faintly: "Okay, how can we find the so-called control center from a huge planet next?" ”

"It's obviously impossible to find it directly." Zhou Xin rubbed his forehead with a headache, "Let's not say that we can't do it at all, and the time doesn't allow it, we still have to find a way to guess the approximate scope of the control center." ”

"But now that there are so many ruins of towns under the sea, how on earth are we going to determine which ruins are hiding the other party's control center?" Spred asked helplessly......