The ancient return was exposed by his sister's live stream.

It contains traces of life that once existed.

The stone-carved couch has a peculiar shape, unlike the standard sleeping platform for humans. It is longer and wider, with a depression in the middle, resembling the outline of some large quadrupedal creature lying down.

There were broken utensils in the corner. A huge stone bowl, more than half a meter in diameter.

Scattered nearby were several bones, not the bones of prey, but tools. Sharpened, they resembled some kind of rudimentary carving knife.

"It has lived here for a long time," Chen Siyao said.

Yang Wanqing squatted down next to the stone bowl and reached out to touch the rim of the bowl.

The bowl has wear and tear, marks left by years of use.

"How many years?" Yang Wanqing asked, his voice much softer than usual. "One person has been here for tens of thousands of years."

She stood up and dusted off her knees.

They didn't say anything more.

The two explored all the branch caves. Chen Siyao used a recording crystal to document the entire process, leaving no corner untouched.

There were claw marks on the cave walls, not from a battle, but more like marks made out of boredom. Some of the claw marks had words carved next to them, ancient script, simple phrases.

Chen Siyao saw a line of words on the wall at the deepest part of the wall.

She stopped in her tracks.

I spent a while identifying it.

"When will you return?"

The three characters were carved very shallowly and were positioned very low, about twenty centimeters from the ground.

It looks like it was carved casually while lying on the ground.

Chen Siyao stared at those three words for a long time.

Yang Wanqing leaned closer for a glance, but didn't say anything. She turned and walked towards the cave entrance.

Chen Siyao took a picture of the three words and then went outside.

Outside the cave.

Chen Hao stood at the edge of the platform, his back to them, looking at the distant ice field.

Jupiter was still overhead, occupying most of the sky, its stripes flowing slowly. This time, Yang Wanqing didn't mention the fear of giant objects again; instead, she turned her gaze away from the sky and moved closer to Chen Siyao.

"Where to next?" Chen Siyao asked, walking up to Chen Hao.

Chen Hao turned around. He glanced at the two women to make sure they were alright, then said three words.

"Below the ice."

Yang Wanqing was stunned.

"Below? Under the ice?"

Chen Hao didn't explain further. He stepped off the edge of the platform and sank down.

It's not falling, it's wearing through.

His body passed right through the ice, as if the ice didn't exist for him at all.

Chen Siyao reacted quickly. Since her brother had gone inside, it meant he was safe. She tugged at Yang Wanqing's arm, "Follow me."

The two then descended.

As she approached the ice, Chen Siyao thought there would be obstacles, but there weren't.

A layer of warm, spiritual energy enveloped them, like a pre-set protective shield. Their toes touched the ice, and then they passed through it.

Inside the ice, it was dark.

All I could see was a translucent grayish-blue. Ice. Endless ice.

They are sinking. Very fast.

Ten meters. Fifty meters. One hundred meters.

It's still ice.

Three hundred meters. Five hundred meters.

It's still ice.

Yang Wanqing's vocal cords tightened: "Yao... just how thick is this ice?"

Chen Siyao was also doing the mental calculations. Based on her understanding of Ganymede, the ice layer of this moon was theoretically over one hundred kilometers thick.

"It might be...very thick."

"How thick?"

"Hundreds of kilometers."

Yang Wanqing: "..."

She shut up.

Fortunately, they didn't actually cross a hundred kilometers of ice. After descending about two kilometers, Chen Hao stopped.

A cavity appeared in front of them.

A huge, dark cavity.

Chen Hao raised his hand, and a ball of white light floated out from his palm, illuminating the center of the cavity.

The light illuminated everything.

Chen Siyao saw it clearly.

This is a natural cave, no, not entirely natural.

There are traces of human intervention on the cave walls; the ice surface has been smoothed out, and steps and passages have been carved out in some places.

The cavity is very large, roughly the size of two football fields.

But what caught her attention most were the buildings.

Ice house.

There are more than a dozen hemispherical igloos scattered throughout the cavity.

Each one is of different height, the larger ones are three or four meters high, and the smaller ones are only a little over one person tall.

The ice walls were transparent, and the furnishings inside were vaguely visible: stone platforms, shelves, and some utensils whose names I didn't know.

Some igloos have collapsed. Others remain intact.

"Someone used to live here," Chen Siyao said.

"It's not human," Chen Hao said, standing next to the light source. "It's a Mystic Frost Ice Butterfly."

"An ice butterfly?" Yang Wanqing leaned closer. "What's that?"

"A kind of spirit insect," Chen Hao said. "It feeds on extremely cold air. Its wings can cut through spatial rifts in the cold wind. Back in the Thirty-Third Heaven, they were the original inhabitants of the Southern Heavenly Gate region."

Chen Siyao asked, "Didn't they migrate along with them?"

"This ethnic group has a unique constitution; they cannot survive outside of extreme cold. The climate of the places they migrated to might not be suitable for them. Therefore, some of them remained."

They stayed behind again.

Yang Wanqing looked around. "Are they... still there?"

Chen Hao did not answer the question. He walked deeper into the cavity.

Chen Siyao and Yang Wanqing followed. The camera lens of the photo crystal slowly swept across the cavity, recording every igloo and every detail.

The live stream chat was relatively quiet—most people were stunned by this world beneath the ice. Only a few comments popped up occasionally.

"There are remnants of a civilization beneath the ice... This is insane."

"The Frost Butterfly... is this an ancient spirit insect?"

"If it's still alive... that's a species from ten thousand years ago."

Chen Siyao walked and looked around. She paused for a few seconds in front of each igloo, observing what was inside through the transparent ice walls.

In the third igloo, she saw scratches on the wall.

Neat, repetitive scratches. One after another, densely covering the entire ice wall.

Counting.

To keep track of dates.

"They're counting the days," Chen Siyao said softly.

Yang Wanqing saw it too. She didn't say anything, tugged at the strap of her handbag, and followed.

Thirteen igloos. Chen Siyao visited every single one of them.

The last igloo, the smallest one, contains a wrecked body.

Not very big. Its wingspan is about half a meter when spread out.

Its wings were a translucent ice-blue color, and even though it had been dead for who knows how long, they still reflected a faint light.

The body was withered, but the form remained. Six thin legs were curled up.

Chen Siyao watched for a while.

"They're all gone," she said.

Chen Hao stood at a distance, his back to them.

"Come here," he said.

Chen Siyao and Yang Wanqing walked over.

Chen Hao led them through a narrow passage at the deepest part of the cavity, and they walked about thirty meters deeper.

Then it stopped.

He raised his hand and released another burst of light.

The light illuminated a small area in front of them, the bottom of an ice wall, where there was a groove. Embedded in the groove was something.

Oval-shaped. Palm-sized. Entirely ice-blue, with regular patterns on the surface, resembling those of some kind of creature…