Maozi's evacuation plan is more distinctive, in addition to building underground fortresses with all his might, he also built several undersea cities in several offshore places.

The reason why the underwater city was built is because the seawater can effectively resist giant insects, and living on the bottom of the sea not only does not have the threat of giant insects, but also can obtain enough marine products to supply the city.

Although Mao Zi did not have the opportunity to participate in the space program, the emaciated camel is bigger than a horse, and the background is much higher than that of those second-tier countries.

Maozi also has a trick that no one can learn, they move a large number of people north, to the cold climate of northern Siberia, hoping to use the cold there to defend against aliens.

However, both the Northern Capital and Washington know that the cold can only resist the giant insects, and cannot stop the aliens who live on Europa all year round...... The temperature there is a little lower than in Siberia.

It is impossible for Maozi not to know this, but it is incomprehensible that they still insist on doing so.

In the chaos, a few days passed in a flash, and at this time, the Fourth Fleet had left Mars, and the engineering ships and other non-combat ships returned directly, while the Nanzhou and several other combat ships followed behind Europa unhurriedly, and even the half-crippled Yushan was not spared.

The reason for this is that the Northern Capital judged that Europa's current orbit was very unscientific, and believed that Europa was likely to adjust its direction, so that it would have to use planetary engines, and the fleet followed Callisto in order to wait for the planetary engines to appear, so as to destroy the planetary engines in one fell swoop.

Beidu also knew that this was a hopeless waiting, and if it wasn't for the fact that he couldn't think of other ways, Beidu wouldn't have made such a move.

After receiving the order of the Nanzhou, the Yushan once again began its routine inspection work, speeding away from the fleet and flying towards the front of Ganymede with an extremely light attitude.

Although the Yushan only has only the remaining orbit section, the thruster is not less than half, its thrust-to-weight ratio is the crown of all warships, and the speed can reach twice that of the Nanzhou, Ling Yu values the speed of the Yushan, and orders the Yushan to continue to follow the fleet, whether it is Ye Han or Lin Yi, there is no ability to oppose and can only obey.

The battleship flew in front of Europa, and Lin Yi glanced at Calmede casually: "Chief, the lava lake seems to have frozen." ”

"Really? It's fast enough. Ye Han muttered unexpectedly, adjusted the direction of the optical lens, and aimed at the lava lake on the surface of Europa.

Sure enough, as Lin Yi said, the edges of several lava lakes had obvious solidification, and the edges that had solidified were covered with a dark metallic luster.

Ye Han frowned, metallic luster?

His brain was a little dizzy, and he immediately turned on the communication equipment: "Yushan called Nanzhou, the lava lake condensed, and the situation was a little wrong." ”

"What's wrong?"

"It doesn't seem to be magma in the lake......"

"What's not magma?"

"It's like metal, molten metal!"

"What are you kidding?"

"No kidding, it's weird, but it's clear." Speaking of which, Ye Han sent a video to the Nanzhou.

This video caused a shock to the entire fleet, and the main force of the fleet led by the Nanzhou immediately accelerated to follow...... In fact, the main force of the fleet is only three warships, which are all the armed forces of mankind in the vicinity of Europa.

After seeing the condensed lake, Ling Yu, who was extremely shocked, immediately came to the rescue of the earth, and Beidu was also surprised after getting this situation.

Although one of the main components of Phobos is hematite, can it still be smelted into steel?

After careful analysis, it was found that Ye Han made a big oolong, the metal reflection in the video is not solidified lava, but an arched metal floating on the surface of the lava, the length of this thing is at least more than 30 meters, and only a small part is exposed outside, and the part hidden under the rock face is not known how big.

Supposedly, it is not strange for metal to appear in the lava lake, after all, the boulder that hit Ganymede was propelled by a super engine, but this piece of metal is obviously artificial, and it is not a part of a super engine!

Beidu immediately thought of the dungeons all over Europa, and thought that it was likely that the boulder had smashed through the surface and smashed the alien dungeon, and the metal had floated from the bottom of the lava lake to the surface of the lake.

As for why no anomaly was found before, it was very simple, the temperature of the lava lake was too high, the metal was burned to a red state by the high temperature in the lake, the color looked similar to the magma, and the surface of the lava lake was undulating and no one kept staring, so it was not surprising that no floating metal was found.

Moreover, the metal in the lake must be a light metal alloy, or the metal component is hollow inside, otherwise it is impossible to float on the surface of the lake.

This thing is not only light in weight and high in strength, but also very resistant to high temperatures, otherwise it would not have survived the impact of small celestial bodies.

Having come to this conclusion, the Northern Capital casually issued a task asking the Fourth Fleet to carefully count the amount of metal on the lava lake to provide a basis for judging the number of dungeons.

I don't know if I don't check, I was shocked when I checked it, the number of large metal components in the lava was beyond imagination, and more than a thousand pieces were found in the smallest lava lake.

This number is really outrageous, Ling Yu felt that the observation was wrong, and the result of re-checking was still this number, with a little fluctuation in fractions, but the total number did not change much.

Ling Yu was not calm at this time, and in order to confirm the accuracy of the data, he ordered the battleship to launch a missile at the lava lake.

The missile accurately hit the lava lake, and the warhead detonated, stirring up high waves, and between the rolling waves, at least dozens of metal components were floating and sinking.

This scene confirmed the previous observations, and also stunned the people in the bridge.

The news was reported to the Northern Capital, and the Northern Capital immediately organized manual analysis and found that according to the density of metal components obtained from observation, there should be a super-large underground city under the lake, otherwise there should not be so many metal components.

But it's a coincidence that a lava lake is above the dungeon, could it be that everyone is on top of the dungeon? Callisto Zero is never going to be a super dungeon, is it?

The more the situation was analyzed, the more strange it became, and all the analysts were a little confused, and then someone suddenly thought of the hollow theory of Europa, and a thought could not help but arise in their minds, could it be that these metal components are the shell of Europa?

If Europa is wrapped in a thick metal crust on the outside, and the interior is as hollow as speculated, then the low gravity, the lack of lava lakes, and the unreasonable density all have a plausible explanation!

The analyst suddenly realized that all the incomprehensible parts of Europa could make sense, but the answer was so unbelievable!