The equipment on board Explorer 2 is all fixed-position, and apart from the ultrasonic detection system, all other systems can detect is the direction they are facing, after all, Explorer 2 was originally designed to explore caves.

The searchlight is no exception, and the direction it points in is also fixed. Therefore, if you want to observe other directions, you can only rely on the operator to turn the entire robot left and right.

The beams of light from the searchlights could only illuminate a small area in front of them, leaving a large area of darkness beyond the narrow field of view.

The cratered ground is covered with a thick layer of black material that looks very similar to fully fermented humus, and as the crawlers roll it down, you can occasionally see some oddly patterned insect shells tumbling from under the humus.

Explorer 2 staggered through the mud, and instead of moving in a straight line, Chen Zheng and the others stuck to the right edge of the trumpet - according to the "First Law of the Labyrinth", if you feel the wall on your right hand or left hand side and keep going forward, you will definitely reach the exit.

Although the so-called "labyrinth law" or "left/right hand rule" has no way to deal with multi-dimensional, nested structures, it is still applicable for exploration.

The edge of the cave wall slowly advanced for about ten minutes......

Suddenly!

There is a hint of anomaly on the cave wall!

"Stop!"

With Chen Zheng's order, the operator subconsciously stopped Explorer 2.

"Shhh...... What the hell is this place!? Looking at what was on the screen, the man with glasses gasped.

The walls of the cave can be faintly seen red, red, white and white paint, although the gray net on it has been so dense that almost the entire wall is hidden, and you can still get a glimpse of it through the dotted cracks......

…… It's a giant mural!!

Could it be that there really is a civilization hidden deep underground!?

Chen Zheng looked at the screen and was silent.

"Your Excellency...... Do you want to continue? The man with glasses approached Chen Zheng and asked cautiously.

"Well, you guys go ahead first, report me if there's an anomaly." Chen Zheng waved his hand and turned to walk out of the tent.

"Your Excellency!?" The man with glasses chased him out.

"You can come too...... Chen Zheng thought for a moment and beckoned to the man in glasses, "I'm going to build a dust-cleaning device...... What are your thoughts? ”

"Huh!? This ......" The man with glasses didn't keep up with Chen Zheng's train of thought, and only after being asked did he groan and think, "How about the high-pressure air gun?" ”

"Hmm...... Dust affects vision, right? Chen Zheng said as he walked.

"Then add an aspiration device to filter the dust out."

"Then it's better to get a vacuum cleaner ......"

"Uh...... What!? The man in glasses was stunned, apparently he didn't have the word 'vacuum cleaner' in his language.

"It's ......," Chen Zheng described the characteristics of the vacuum cleaner.

"It's not impossible...... However, the strokes seem to be very high, and if you want to make a 'vacuum cleaner', you can only use a sleeve to expand and contract. If you want the sleeve to be stretched high enough, the weight will be a problem...... The strength of the existing material is insufficient, and the external support structure will become complicated......"

"You're right." Chen Zheng thought for a while and nodded in approval, "But the high-pressure air gun also involves the nozzle of high-pressure gas, right?" Although it can be made shorter than a 'vacuum cleaner', if the mural is too high, it will still have the problem you said. ”

"Well, that's right." The man with glasses frowned deeply, "Otherwise, we will directly install the air pump on the mechanical arm - the mechanical arm does not have the problem of external support structure, and can be built very high." ”

“…… Yes, that's it. ”

After discussing the requirements, the two drove Explorer 3 out and began to modify it according to the previous design.

Explorer 3 abandoned life, ultrasound and other detection devices, leaving only the video system and lighting system.

This time, the camera is mounted on a hemispherical "turret" that can be tilted and rotated 360 degrees, and the camera's long lens becomes the "barrel", and on both sides of the "barrel" are more powerful and variable-focus searchlights.

Behind the turret are two long robotic arms, one of which carries the "Ionic Wind" generator. Although the so-called ionic wind may sound like a tall one, it actually looks like an ordinary metal cylinder.

The principle of ionic wind generators is much like that of a heaper, using electrical energy to generate an 'electric' force to create airflow. When the ionic wind generator was built, Chen Zheng deliberately tested it, and although it was not enough for the airflow strength of the "high-pressure air pump", it was enough.

In addition to the No. 1 robotic arm loaded with the "hair dryer", the No. 2 robotic arm has a slightly fewer number of folding layers, and the longest is no more than 3 meters. 2. The top of the good robotic arm is a "Y" shaped claw structure.

When Explorer 3 has a "hand", it can not only collect specimens, but also drag the wreckage of Explorer 1 back.

Just as the two of them had completed their transformation of Explorer III, the man with glasses suddenly received a call from other researchers.

"Your Excellency...... You should definitely check this out. ”

As soon as Chen Zheng entered the tent, a researcher greeted him and pointed to the screen.

"It's ...... Eggshell!? Chen Zheng looked at the gray-white oval flakes on the screen, and exclaimed with an incredulous expression: "How could the bullet case be of this shape!?" ”

“……”

There was silence in the tent.

"How did you find this!?" Chen Zheng pointed to something on the screen and frowned.

"Well, just after we left the mural, we saw a line of footprints...... Then I followed the footprints and found these things. ”

As he spoke, Explorer 2's screen spun in a different direction......

It's a small, cylindrical space, with only the entrance and exit being the hole where Explorer 2 enters.

In addition to the hole, this small space is filled with a variety of carapaces...... And they still look very fresh!!

Some carapaces even have teeth gnawed on them!

"Are there any results of these tooth marks?" Chen Zheng asked.

"Yes, here."

With the researcher's movements, a report was sent to Chen's personal terminal. Chen Zhengmo had the patience to look at the data, and directly pulled the report to the bottom, only to see that it was written......

“…… Suspected of some kind of Homo sapiens of the primate earthfamily!? Chen Zheng pointed to the final conclusion and frowned.

"Ahem, ahem...... Damn it! What primate Homo sapiens ...... Change them all to earthlings! No, change to the great earthlings! "The way the man with glasses slaps his ass, is extremely clumsy.

“…… It's good to change it to an earthling. Chen Zhengqiang resisted the urge to roll his eyes.

"Two move on, and two people are assigned to take control of Three."

"Yes."

As everyone was busy, Explorer 3 also started smoothly, and followed the path of 2 straight to the cave ......