The leader of Suihe was stunned, and was very surprised by Ye Han's order: "Chief, withdraw now?" ”

"Yes, the drone stays, and everyone retreats!" Ye Han said.

"Understood, withdraw immediately...... Chief, do you need to go in and see if you use the drone? ”

Ye Han hesitated, but he immediately made a decision: "No, just find a place where you can monitor the ice cave." ”

"Understood!"

At the end of the communication, Ye Han thought about it and said on the radio: "Attention units, our mission is to reconnoiter the situation under the ice, not to fight with aliens, and to monitor suspected targets with drones, try not to alarm the enemy." ”

"Suihe Group received!"

"Shihe Group received!"

"Baoshan Group received!"

"The Pinghe Group received ......"

The groups replied quickly, and Ye Han went through the sieves one by one, and was not relieved until he was sure that all the reconnaissance groups had received orders.

The operation continued, with the Suihe Jinyu in front, all groups paid a little more attention to the ice wall, and successively discovered several ice caves, some of these ice caves are new and some are old, and there is a hole that is half covered by vines, if it is not for the soldiers to be careful, they must have missed it.

The fighters carried out the orders in the course of the reconnaissance, all targets were monitored by drones, and no one approached without permission.

Ye Han didn't expect the reconnaissance operation to hide from the aliens, he only wanted to delay the time for the aliens to get the news.

But he never expected that in the corners that the soldiers couldn't notice, a pair of eyes hidden underwater were always watching the actions of the soldiers, and the so-called don't alarm the enemy was a joke at all.

If Ye Han knew that all his actions were under the surveillance of aliens, he was afraid that he would immediately order to withdraw from the ice.

Fortunately, he didn't know yet, so the reconnaissance had to continue.

No abnormalities were found on the water, and Ye Han turned his gaze to the water again, but the team members in charge of underwater reconnaissance also found nothing.

This time, Ye Hanke made a difficulty, hesitated for a while, and first ordered all the team members to return to the vicinity of the ice cave where they came, and then ordered each group to manipulate the drone into the ice cave suspected of harboring aliens.

Half an hour later, Ye Han wanted to communicate with the flagship: "Commander, we have found traces of alien activity in the ice cave, very obvious traces, unless Europa has evolved intelligent creatures, there is no way to explain those things in the ice cave."

Huo Qiang asked reluctantly: "Didn't you find any useful clues?" ”

"Nope!" Ye Han said, "I didn't find any useful clues, and the enemy didn't leave anything superfluous, the enemy should have evacuated the ice cave in an orderly manner." ”

Huo Qiang sighed and looked up at the others: "What do you think?" ”

Zhuang Bo withdrew his gaze from the holographic map of the space under the ice: "It's hard to say anything else for the time being, but our reconnaissance direction is right." ”

Wu Han also said: "It's not been a day or two that the enemy has been running Europa, and it will not be easy for us to find this clue when we are new here!" ”

Huo Qiang pursed his lips: "Ye Han, what's going on underwater?" ”

"I didn't find it, the water was too deep, and the soldiers relied on the naked eye to observe, and the range they could see was too small." Ye Han poured bitter water, "Chief, no one knows how deep this place is?" ”

Huo Qiang said: "I just received a reply that the average thickness of Europa's ice is about 100 kilometers, and the depth of the sea is between 25 and 100 kilometers, but this is all calculated by the strength of the magnetic field, and it is all speculation, and none of them are accurate." ”

"Commander, can't you find a way to measure the depth of the water?" Ye Han glanced at the water, Huo Qiang didn't say that he had forgotten that the landing reconnaissance force was not only the first time that humans had landed on Europa, but also the first time they had entered the ice, and such a strong experience was enough to be written into the history books.

"Thought." Huo Qiang said, "According to Deputy Commander Zhuang's suggestion, I asked for a sonar drawing with Bei, and now we are printing parts!" ”

"Great!" Finally hearing a piece of good news, Ye Han was overjoyed, "How long will it take?" ”

"It takes about half an hour to finish the parts, and it takes half an hour to send them over for assembly, so it takes about two hours."

Space fleets often go on long-distance missions, often for months at a time, with no chance to return to base during the mission, and space on board is precious, so there is not as much space to carry vulnerable parts.

In order to solve this problem, every human warship has a maintenance pod, and the most important equipment in the pod is a 3D printer, and the small and medium-sized parts needed by the warship can be obtained by printing.

Sonar is not a simple part, but a complete set of equipment, in order to speed up, Huo Qiang disassembled the sonar drawings, each battleship is responsible for one or several parts, and then concentrated on the flagship assembly after printing, to save time to the greatest extent.

"Understood...... Chief, I've seen everything I can see, there's no need to keep staring at the places I've seen, I want to withdraw the people first, and then check the underwater situation after the sonar is sent down...... When you have sonar, you can dig out the enemy even if they are hiding in the water! ”

Huo Qiang said: "You can just look at it yourself." ”

"Yes!" Ye Han agreed, and suddenly remembered that a set of ultrasonic detection equipment was integrated on the power armor.

This thing is to supplement the shortcomings of night vision devices and is used to detect underground space, but ultrasound seems to be able to detect water depth!

Thinking of this, Ye Han immediately gave an order, asking the soldier in charge of reconnaissance underwater to see if the ultrasound could find something.

The fighters who received the order immediately took action, turned over and dived into the water, and turned on the ultrasound equipment facing the bottom.

This scene is all watched by the eyes hidden in the shadows, they are silently hidden in the darkness, without the slightest intention of intervening.

However, in the next second, the piercing ultrasound pierced the ear drums of the mysterious creatures like a magic sound, and they instinctively rolled over and dived underwater, and the fierce movements set off a splash, and the layers of water waves spread rapidly.

The mystical creatures are all hidden in the inconspicuous corners, and their movements are loud but they don't attract the attention of the team members - except for the warrior who is soaked in the water!

The ultrasound is constantly running, and the feedback information is displayed directly in front of the soldier's eyes, and the screen is normal one second, but the next second there are a few more things swimming at high speed.

The soldier's expression immediately froze, and comparing the two images before and after, it only took one second for seven or eight targets to dive from the surface to more than ten meters underwater, which was astonishingly fast.

And that's just close, there are more anomalous echoes a little farther away, more than forty of which can be discerned.

The fighter rolled over and jumped out of the water, rolled over and fell into the rubber boat: "There is something under the water!" ”

"What's that?" The team leader asked.

"I don't know, it's very fast, it's going underwater!"