With three superpowers at his fingertips, he could dominate the 1970s.

When the three-day deadline arrived, Jiang Zhiyu promptly pushed open the door to the top-secret conference room.

The room was already full of people, including the leaders of all five groups. A large, pieced-together map was spread out on the conference table, stretching from one end to the other, with teacups weighing down the four corners. She leaned closer to look; it was a complete map of the moon, black and white, densely covered with the shadows of craters. Several areas were circled in red pencil, and not just once, showing that the person who drew it had traced it repeatedly.

When Old Gao saw her come in, he raised his chin.

"Everyone's here. Astronomy group, geology group, you two go first. Director Jiang, these old guys haven't slept a wink for the past three days; they've practically worn out this map."

The old astronomy professor stood up, holding a thin bamboo stick as a pointer, and his first words were a sigh.

"Director Jiang, let me be frank with you first. We've been looking at the moon with telescopes on Earth for so many years, and what can we clearly see? Lunar maria, craters, lunar ridges—these are landforms several kilometers or tens of kilometers in size. The kind of cave entrance you're looking for, tens or hundreds of meters in size, would be just a pinhead in a telescope; we can't see it."

Jiang Zhiyu was stunned for a moment.

"What's circled on this picture?"

"The circled area is the most likely to have a hole," the veteran geologist continued, pointing to a darker area on the map. "Director Jiang, let me ask you something first: do you know how the lunar maria came to be?"

"You said."

"The lunar maria are not seas, but vast plains formed by lava erupted from volcanoes long ago, which then cooled and spread out. As the lava flowed, the surface cooled first, forming a hard crust. The lava continued to flow beneath the crust, eventually emptying out and leaving a conduit – the lava pipe. Over time, a section of the top of the pipe collapsed, revealing a skylight, which is the entrance you are looking for."

The old professor's bamboo pole fell down and touched a winding, thin line on the map.

"So how do we know where the pipe is buried? That's where the Moon Creek comes in. These winding gullies are called meandering Moon Creeks, and they're river channels carved out by lava flows. Some creeks are completely open, while others flow underground and become subterranean rivers. The subterranean sections are most likely where lava pipes lie. So to find the pipe, first look for the creek, then follow it, and finally look for the collapsed section of the creek roof."

"We can't see the skylights, but when they collapse, the area around the opening is often piled with rubble. With careful comparison, you can see a small dark patch on the bank," the veteran geologist added. "Over the past three days, we've retrieved all the lunar surface photos taken by various observatories across the country over the past thirty years and compared them one by one. We've circled all the areas on the near side of the moon, in the mid-to-low latitudes, at the edges of the lunar maria, where lunar rivulets are dense, and which also contain what appears to be a dark patch."

The old professor used his bamboo pole to mark circles from the west to the east of the diagram, one circle after another.

"Seed One, Ocean of Storms, Marius Hills. This area is the most volcanically active on the moon, with volcanic domes one after another and lunar rivulets branching out like a spider web. We suspect that the entire hills are riddled with interconnected lava tubes. This is Seed Number One."

"Number Two, Schröder Valley, the largest winding lunar stream on the moon, located in the northeast corner of Oceanus Procellarum, is over a hundred kilometers long, and its source is a crater nicknamed Cobra's Head. Given the size of the lunar stream, the pipes underneath must be quite large."

"Number Three, southeast of Mare Imbrium, at the foot of the Apennine Mountains, in the Crescent River Belt. The area where the Mare Imbrium meets the mountains was where the most lava flows occurred, and there should be a lot of lava there."

"Number 4: North shore of Chenghai. Number 5: Southeast of Jinghai. Number 6: Northeast edge of Yunhai."

The bamboo pole paused once on each of the six red circles.

"Six sections, all on the near side of the moon, all on the terminator; we've already passed the hurdle of temperature."

Jiang Zhiyu bent over the drawing, memorizing the shapes and positions.

"There's also the matter of timing." The old professor pulled out a piece of paper from the side, densely covered with numbers. "The terminator orbits the moon once a month, and for each section, there are only a few days each month when the terminator passes right through it—the weather is neither too hot nor too cold. We've calculated all six windows of opportunity for the second half of this year; which day to go to which point is clearly listed on the table. The temperature inside the cave is stable year-round, but when you come out of the cave to travel or find the entrance, you can't exactly search under the 120-degree sun."

"Host, they don't know you have a cheat code!"

Jiang Zhiyu nodded. She hadn't used it yet, but this window period chart would be useful later.

"Once we get there, please tell me exactly what we need to see," she said.

The veteran geologist had been waiting for this, and he took out a piece of paper folded into four sections from his pocket. When he unfolded it, there were six handwritten points on it.

"First, how big is the entrance, what's its diameter, and can people and equipment enter? Second, how high and wide is the cave, what's its orientation, straight or curved, and how far can one go inside? Third, how thick is the rock layer on the cave ceiling? Thicker rock is needed to withstand radiation and micrometeorites. Fourth, what's the temperature inside the cave? Fifth, is the area around the entrance flat? There needs to be a level surface for landing and unloading. Sixth..."

The old man paused, his expression so serious it was almost comical.

"Please check if the cave is clean and if there's anything else inside."

Jiang Zhiyu couldn't help but laugh.

Are you afraid there are moon people in the cave?

"I'm afraid of everything," the old man said seriously. "The rocks on the moon don't lie, but who knows what's going on on the moon?"

The people in the room burst into laughter. After they finished laughing, the old astronomy professor handed them a brown paper bag.

"Director Jiang, there's one more thing. Once you're on the moon, there are no landmarks. How will you know where you are? Here are six maps, one enlarged version of each section. The craters are all labeled, and the spatial relationships between them are clearly drawn. When you land, the first thing you'll recognize is these mountains. Once you align three mountains, you'll know where you are. There's no atmosphere on the moon, so the mountain shadows are very sharp, making it even easier to find your way than on Earth."

Jiang Zhiyu took the paper bag. The picture was freshly printed, a thick stack, and it still smelled of ink.

What about communications?

"Always face Earth, the radio will get back." An intelligence officer handed over a palm-sized metal box. "Miniature radio, frequency tuned. When you get to your location, turn it on and press the talk button, and you'll get a response on the ground. There's no atmosphere on the moon, so the signal travels in a straight line. As long as you're on the near side of the moon, there shouldn't be any problem."

He paused, then smiled.

"If all else fails, you can travel back and forth, right? You can come back every day for a hot meal and a warm bed; that's more reliable than any radio station."

The roommates laughed again. Old Gao hadn't said a word until the laughter stopped, then he spoke, his voice not loud, but authoritative enough to command the room.

"Director Jiang, this matter isn't urgent. Six points, six trips in total. If you don't understand something in one trip, go twice. People are the priority. Once you get there, if you feel something is wrong, come back immediately, understand?"

Jiang Zhiyu packed everything up and nodded to him.

She turned her head again and looked at the old geology expert.

"Don't worry, sir, I'll find you a few more stones."

The old man's lips moved, but he didn't say anything. He cupped his hands in a gesture of respect towards her, and his eyes were a little red again.

……

When they got home, it was already completely dark. Jiang Zhiyu spread out the six lunar maps one by one on the table and turned the lamp as close to the light as possible. Seventeen shrank down and squatted beside the lamp base, her two metal legs dangling in the air, and also looked at the maps one by one.

"Host, there are six points, which one should we go to first?"

Jiang Zhiyu's fingertip landed on the westernmost red circle, the Storm Ocean, Marius Hills.

"Number One. The place with the most volcanoes, and also the most caves."