The party went into Sophia's house. As it was built underground, the room was not very high. That didn't stop this cat from decorating her home, though. The walls, like her cafe, were painted coffee and smelled of cocoa beans. The ceiling was painted with a mix of brown, pink and green paint, and the floor was glossy rosewood. As they stepped on it, the characteristic aroma of the rosewood evaporated and filled the air. The lamps on the wall shone bright yellow on a round mirror. Next to the mirror was a fireplace where the coals were still burning brightly. The orange firelight warmed the whole room and reflected Ranran's pink face. In the middle of the room was a large circular table made of a single block of rosewood, with several bronze-colored benches beside it. In the corner, there was a silver sofa with a lot of soft cotton in it, so it was surprisingly soft and comfortable. Even though he was extremely tired, one's body and mind would immediately rest if he lay on it. At the other end of the room stood several storage bins, each with a gold lace cover and a clear view of the carbon fiber texture. If he smelled carefully, one could also detect the aroma of sycamore wood, which came from the coating inside the box.

"Please take your seats," Sophia said, turning to rummaging through a storage box.

"What are you looking for?" William asked.

"Oh, here it is! That's it!" The cat took out a small blue panel and walked over to the fan. She also took out the screwdriver, removed the broken panel from his head, and put the new one back in.

"I made it myself! Does it fit?" She asked expectantly.

"Hmm... So comfortable! Yours should be the most comfortable one in the whole universe!" The fan replied agreeably.

"Oh, thank you for your praise..." Sophia smiled shyly.

"How can you make these things?" Asked Photon with great interest.

"Well, I did it all in my spare time." Sophia pulled out a few more small objects, including a stone she had carefully carved. It was the shape of a boat, with its windows clearly visible.

"Wow, I didn't know you were a buried craftsman!" Natalie exclaimed after taking a closer look.

"No, no, I'm just playing." Said the cat humbly. Then she remembered something else, so she added, "Oh yes!"

"What do you remember?" Ranran asked.

"Something strange has been happening in my garden lately." There was an anxious look on the tabby cat's face as she twitched her whiskers.

"Like what?" William asked.

"I find, for example, that my violets are growing particularly well, for no apparent reason. I did not deliberately gave them more water, more fertilizer or more mother star's light, but why are their petals always clear?"

"This is indeed very strange. Maybe someone helped you when you didn't see it." Grumbled Photon.

"And I often find little gold bars in the ground! Each piece is very regular, and sometimes there are symbols on it that I don't understand!"

"Then this is stranger. Who did it?" Photon's tone was even more exaggerated than last time, "Did you see any special marks on it?"

"No, but I've got a lot. Look, these are gold bars I found in the garden." The cat opened another locker and hundreds of glittering gold bars came into view.

"Wow... You made a fortune!" There were golden stars in Photon's eyes. He also turned the propeller to show his surprise.

The coals were still burning, and the room was warm. The mirror reflected the yellow light from the lamps on the wall.

Sophia the tabby continued, "And there are more strange things. Today, I came to the garden as usual, only to find a special sign! It was in the shape of an arrow, pointing down, and it said, 'The mystery is below.' "

"Did you dig down? Did you find anything?" William continued to ask.

"No. Because I saw a sentence on the back of the sign, 'Pick up this chip and explore in your dreams!' "

"What?" William jumped up in surprise, "Explore in your dreams?"

"Yes, that's what it said on the sign and on the back of this chip." Tabby said, taking out the little chip she had found. William took it, and saw that it was not very different with those the earthmen could made. The only difference was that its back was engraved on the words behind the sign.

"Explore in your dreams... Are we supposed to go underground while we sleep? How can that be?" Ranran thought.

Then this chip flew up to William's ear and pressed gently against his skin. Then a voice said, "Exploring in your dreams means that when you are deep asleep, your minds will go explore!"

Then it flew back into the heart of his hand.

"The chip told me that when we are in deep sleep our minds will go explore..." William hesitated, not understanding the chip at all.

"Minds explore? Ha ha, did you hear that correctly? How can that be!" Natalie laughed loudly.

"No, I certainly did. I understood every word, but I just didn't understand what this chip meant."

"I thought the chip must be joking. There's no such thing as a 'minds explore' -- what you are going to explore will just be a dream." Photon calmly analyzed, then turned to the tabby cat and said, "Ms Sophia, I think this chip is lying."

"Is there any evidence that it's lying?" Tabby asked, in a tone that suggested she was sure.

Photon was about to produce the strong proof he had just mentioned, but he froze again. He didn't expect Sophia to believe so much the chip.

The others were so surprised by Sophia's determination that they too began to believe the chip. But an established view had always been ingrained in their minds, which was that they believed that the so-called "minds explore" did not exist. For a moment there was only the beeping, bobbing sound of burning coals in the room.

"So is it true or false?" Ranran asked after a few minutes' silence.

"Are we going to wait like this forever?" The plane said.

"That seems to be the only way to go," William deadpanned, "because we haven't tried. And tonight will be a great opportunity."

"That's right." Natalie the racing car said, "But I'm curious what we'll get tomorrow morning if it's true."

"I bet you'll get it," The fan spoke after a moment's silence.

"Why are you so sure, Mr Hagar?" A strange gleam came into William's eyes.

"Because, on the way in, I saw in the distance in the violet gardens a very small archy opening, with what seemed to be a ghost sign painted beside it. But I'm not sure whether the violets are yours, Ms Sophia."

Tabby nodded immediately after the fan briefly described the location of the violets. "Are you sure what you saw is true?" She asked the fan hesitantly.

"I'm pretty sure. It's a size you might all overlook, but the two things I trust most are my eyes and my brain."

"And how big do you guess the opening is?" William demanded.

"Not very big. But there's no way any of us can get in."

No one spoke again, and there was another silence.

Tabby cat saw that there were few coals left in the fireplace, so she got up, ready to add more. The others still sat at the table in silence. William looked nervous.

"I'm worried." He said, "I'm worried that something might fly out of the ground at night and find us..."

Before he had finished, Sophia came back with some charcoal.

"I have just proved with my binoculars what Mr Fan saw." She said, her face white.

"Did you see anything else?" Ranran asked anxiously.

"That ghost sign is real. I didn't see anything else."

"What do you think is going to be down there..." Ranran whispered in William's ear again.

He shook his head and whispered, "I don't dare to think... I think anything could come out of that... What if they find us in the middle of the night when we're asleep... I wonder what's going to happen..."

The atmosphere was suddenly heavy, as if the air had stopped flowing for a moment. At the beginning of the silence, the faint noise of the distant street could be heard, but now the silence was deathly. The flames in the fireplace dimmed. The next moment a hand seemed to press down on them so hard that they could not breathe.

But a few seconds later, the atmosphere was suddenly normal again. The strange hand had disappeared without a trace. In the room were the same yellow lamps, the blazing fireplace, the big round table, and the party on the stools. In the last hour, it seemed that nothing had happened. But there was a shadow on each of them because they had no idea what was going to happen tonight. As William had feared, something would come out and find them while they were asleep, and then? Or, as the chip said, would their minds explore the depths of the earth, and what unexpected surprises would they find tomorrow morning? Or was it neither?

The party sat there for a while again, all silent, until drowsiness swept over them. Under Sophia's arrangement, they lay down, and within a few minutes, they were all asleep.

The fireplace was the only light in the room. Its playful tongue of orange fire reflected the faces of the party, asleep. William smiled a little. Maybe something good happened to him? But what was worrying was that soon it would be time to verify whether what was on the chip was true.

Outside the house, on the road, the crowd began to thin. An hour later, the street was empty. There was only the yellow light of the street lamps reflecting the dancing snow and the thousands of stars inlaid in the night.

The room was very quiet. Wish tonight a safe eve...