Chen Hao squatted down in front of the snow-covered ground, but pulled his fingers back as soon as they touched the snow.

“Something’s wrong with this snow,” he said. “It makes no sound when you step on it.”

Nana walked over, and the robotic arm extended its scanning module. The screen lit up, and the data stream began to scroll. She didn't speak, but simply projected the test results onto a small panel in her palm.

Chen Hao leaned closer to take a look. "Protein again? There wasn't any of this when we were collecting iron filings last time."

“It’s not a human or known animal residue,” she said. “The abnormal keratin fiber structure suggests it originated from the epidermal tissue of a large organism.”

"Wait a minute." Chen Hao took half a step back. "You mean, something walked by here, and it's shedding skin flakes?"

"Judging from the marks, it weighed at least 300 kilograms, walked upright on two legs, and had a stride of 1.8 meters."

"Isn't that just a refrigerator wearing snow boots?"

Nana put away her equipment. "The footprints extended towards the north rock face, and were covered by wind and snow along the way, but a faint heat signal still remained."

"You can actually tell?"

"The drone is retracing its path."

They followed the signs down into the valley. The snow grew harder and harder, feeling like walking on frozen mud. Chen Hao struggled to walk, having to lift his leg before pressing down hard with each step to avoid slipping. When he reached a slope, his foot slipped, and he fell sideways into a snowdrift.

“I’m fine,” he said, lying on the ground. “I just wanted to check the ground’s hardness.”

Nana stopped and turned to watch him climb out of the snow; his hat had fallen off, and his hair was covered in ice chips. She handed him a telescopic pole with a light and a camera attached.

"There is a gravel area ahead, I suggest you keep your distance."

"Are you afraid I'll roll down and break the equipment?"

"I'm afraid you'll complain of being tired after you fall down."

Chen Hao took the pole and probed the way forward. The scree slope wasn't steep, but a thin layer of ice covered the surface, making it slippery. He changed to walking sideways, placing one foot firmly before moving the other, like a clumsy crab.

After walking for twenty minutes, the footprints reappeared. Three parallel indentations with neat edges and slight drag marks at the bottom.

“This didn’t happen by walking out,” Chen Hao said, bending down to gesture. “It stopped standing for a moment, then turned around and walked away.”

“Agreed.” Nana moved closer to take the picture. “The last movement was directed towards a crack in the rock wall, about 150 meters away.”

"So, it went home?"

"Or perhaps, that was originally its territory."

The sky gradually darkened. The wind subsided a bit, but the temperature dropped even faster. Chen Hao rubbed his arms, his teeth chattering slightly.

“We can still make it back now,” he said. “We’ll bring our equipment back tomorrow.”

"Didn't you just say you wanted to see if there were any parts inside?"

"That's because I hadn't realized I might become a cog in the machine."

Nana continued walking forward. Chen Hao hesitated for a few seconds, but finally followed her.

They rounded a protruding rock, and their view suddenly opened up. Beneath the north rock face was a crevice, about two meters wide, partially blocked by collapsed snow and ice. As they approached, the footprints on the ground became more numerous, the deepest one nearly ten centimeters deep.

“Entrance confirmed,” Nana said. “The interior space can be preliminarily surveyed using the probe sphere.”

She took a small silver-gray ball from her backpack and pressed the start button. The ball separated into three sections, with miniature tracks unfolding in the middle and a red light illuminating the front.

"This thing looks like expired capsule medicine," Chen Hao said.

"It functions perfectly."

Nana remotely controlled the ball to enter the hole. The image was transmitted wirelessly back to her terminal: the passage sloped downwards, the inner walls were covered with light-colored crystals, and the ground was dry with no snow. After traveling ten meters, a fork in the road appeared ahead, and the probe ball stopped moving forward.

"Air composition is normal, oxygen content is 21%, and temperature is constant at 12 degrees Celsius."

"It's warmer than outside."

"No severe vital signs, no heartbeat or respiratory rate detected."

"That doesn't mean there's no one."

"It doesn't mean there are any people."

Chen Hao stared at the still image on the screen. The depths of the passage were pitch black, and the red light could not reach the end.

Do you think it might only come out at night?

"There is currently no evidence to support the diurnal activity pattern."

"What if it's hibernating? Should we wake it up?"

"Then you should be glad it's daytime."

He felt for the flashlight in his pocket, then put it back. "How about we retreat first? And bring a few more people tomorrow?"

"It's just the two of us."

“I know… but I can pretend there are other people.”

Nana has already begun setting up the security system. She installed four vibration sensors around the cave entrance, connected to portable alarms. She also set up two automatic lights, configured to activate automatically upon contact with a sensor.

"We're taking turns on duty tonight," she said. "I'm on the first shift."

"Do we really have to spend the night here?"

"A tracking interruption means information is lost. We need to confirm whether it will return overnight."

Chen Hao sighed and unloaded the winter shelter components from the sled. The supports kept tilting to one side when inserted into the frozen ground, so he simply used stones to weigh down the base. After setting it up, he crawled inside and found the ceiling was so low he could only sit down.

"I feel like a penguin trapped in a tent."

"You definitely need to keep warm."

He unfolded the thermal blanket and wrapped it around his body, leaning against the corner, panting. It was completely dark outside, with only the occasional red flash of the streetlights.

"What do you think it eats?"

"unknown."

"Such a big guy can't just eat snow all the time, can he?"

"The possibility of carrion feeding or hunting cannot be ruled out."

"We're doomed." Chen Hao pulled the blanket tighter. "If it gets hungry, I'll be its first target."

"Your fat reserves are indeed more noticeable."

"You actually said that?"

"I'm just stating the facts."

Time passed slowly. Chen Hao was so sleepy that his eyelids were drooping, but every time he closed his eyes, he thought of that string of footprints. He sat up straight, took out the sampling bottle, and looked at the snow particles inside.

"Can this thing really detect DNA?"

“Nana’s knowledge base includes a basic biochemical analysis module.”

"What if it's not a life form from Earth at all?"

"Currently, all detected indicators are within the range of carbon-based life forms."

"What if they are aliens disguised as Earth creatures?"

"Then you shouldn't be sleeping alone in the shed."

Chen Hao immediately zipped the jacket up to his neck. "I'm going to check the sensors."

He climbed out of the shed and walked through the snow to the first monitoring point. The indicator light was green, showing no abnormalities. The second one was also normal. The third…

"Nana!"

"What's wrong?"

"The third sensor is not moving."

Nana came over to check. The indicator light was off, and there were minor scratches on the interface.

“It’s not a malfunction,” she said. “It was touched by an external force.”

Chen Hao took a step back. "When did this happen?"

"Within ten minutes."

"Where is it now?"

"have no idea."

The two exchanged a glance. Nana quickly activated the backup detection program, raising the drone to a height of five meters and initiating infrared scanning. Chen Hao, clutching a flashlight, stood with his back pressed against the rock face.

The wind suddenly stopped.

The entire valley fell silent.

There wasn't even the sound of snow falling.

The lights suddenly switched on, and the bright light swept across the left side of the cave entrance. In an instant, Chen Hao saw a shadow on the rock wall—tall, with broad shoulders, and a head that didn't resemble a human's.

The light went out.

Even the shadow has vanished.

Did you see that?

"I saw it."

"That is..."

"uncertain."

Nana retrieved the drone and said in a low voice, "I suggest we move to a different location immediately."

"But all our things are here."

"Including the parts you just said you didn't want to become."

Chen Hao gritted his teeth and turned to dismantle the shed. Just then, a soft sound came from the cave entrance.

It was like a stone rolling down.

It felt like something heavy was gently stepped on the snow.