The party saw a bright light ahead. At last they stepped out of the long, dark underground tunnel and went up to the ground. It was their first glimpse of a planet in a completely alien universe. But the environment still looked a lot like what they thought an Earth-like planet would be like. They looked north now and saw in the distance the great rolling mountains, cleverly clad in a fitting green coat. Illuminated by the blue mother star, it reflected an indescribable and magical color. A little closer to them was a wide river, its water colored due to the enrichment of many complex elements. A few fishes swam gaily in it, with unusually large heads, which was quite different from those of terrestrial fishes, and tails far more complicated. Occasionally a few big-headed waterfowl would catch a few dainty fishes for lunch. Behind them laid the vast plain. To the southwest, patches of rape flowers weaved bright yellow flecks on the mantle of the earth; to the southeast, it was the heaven of violets and tulips. Red, orange and purple naturally blended into a giant circle. Seen from high above, it looked like a pie spread on a yellow and green tray. The earth was excited by these beautiful flowers, so she gave the best nourishment to those colorful flowers, letting them enjoy the breeze.

"Ah, it's like something out of a fairy tale." Ranran took a deep breath of fresh air and said softly.

A gentle breeze kissed the fair faces of them each, tinged with the faint smell of wheat in the distance.

"Let's go on," William said, looking into the distance at the road covered with maple leaves in front of him.

The shoes and tires of the party gently trod and rolled on the extremely soft maple leaves. Another breeze blowing, those leaves that were still playing in the bunches laughed out loud "rustle rustle".

There was a blue arrow about 500 meters away. It pointed to the left and said,

That's where Thomson lives. Keep going. You won't miss it.

They turned a corner and went on the same way for about twenty minutes. From time to time, naughty sparrows flew down and gave a few friendly pecks on their heads. The cuckoos welcomed them with clear voices. A few maple leaves fell silently, falling on Ranran's pink dress. She smiled and put them on her chest.

They did not stop until a huge maple tree and a wooden door appeared in front of them. Near the door was a chocolate sign with the words "Thomson's Tree house" written on it with cream.

"This is it." Said William, stepping forward and knocking gently on the door.

The door opened and out came a blue-gray shorthair cat. He wore a red cap, a striped tie, and shiny shoes. His pair of green eyes was bright. He was holding a red-covered diary book with a somewhat rusty cover.

He looked them all over, then smiled a little.

He said, "I know who you are and what you are doing. Please come in."

Confused, the party followed him into the tree. Thomson clapped his hands and all the lights came on. "Why are your lamps on the branches?" Asked Photon, puzzled.

"Oh, I knitted it myself. I like it because it looks a little more natural."

Thomson pressed another bronzed button and the elevator came down. As they stepped inside one by one, they were surprised to see that the car was made almost entirely of branches and roots. However, graphene and carbon fiber were added by Thomson, which guaranteed heavy loads and strength. The cat pressed the button "5", and the elevator slowly carried the party upward, stopping at a platform. Then the door opened automatically.

"Please, everyone." Said the cat politely.

They entered the room in turn. Looking around, there were strong branches with a bright brown sheen, the ceiling covered with golden maple leaves. The windows on the wall were a perfect combination of tree branches and glass. A ray of mother star's light poured through the window, leaving its blue lip prints on the ground. Several shelves were neatly arranged against the wall, each with several books, some of which were already covered with thick layers of dust. A green sofa was propped in the corner, next to a small tea table, on which stood a bottle of ink, a pen and a thin, blue-covered book.

The cat signaled the others to sit down. William and Ranran settled down on the sofa, while Photon and Natalie were parked against the wall.

"I just said I knew what you were doing. Now each of you read out the numbers for you." Said Thomson, picking up the blue-covered book and turning to a page. He showed William first.

Six two five

The writing glowed green as he read it. The book turned to the next page automatically. The numbers for Ranran were:

Three six zero

She, too, read it, and the writing sparkled again. When Natalie finished reading at last, a blue light flashed in front of them and then disappeared. At the same time, their computer showed,

Checkpoint 1 is cleared. Energy charge: 1.5%.

"Wow, this amazing?" William exclaimed.

"Sure." Answered Thomson, "This pen of mine uses special ink!"

"Wow," Ranran smiled, too.

"Let me show you something," Said Thomson the shorthair cat. He opened the red-covered diary book to Page 1.

"This is a sad story." He said, a little sobbing.

"What's the matter?"

"Well," He replied to puzzled Natalie, "this was a huge mistake of mine.

"It was three years ago, in the lab downstairs, that I finished the greatest project on the planet -- the creation of another cat using gene editing. With my specially engineered gene, he can even resist a terminal disease in cats! At that moment, I felt the whole universe lit up. When I heard his first clear and loud cry, my heart almost melted!

" 'I am great, Thomson.' I said to myself, 'This is a moment that will always be remembered by the planet.'

"So, because of the cat's preciousness, I vowed that I would nurture it. I was there for him all the time, gave him food he wanted, dressed him in the clothes he wanted, and never once made him sick.

"Then one day he saw me in the lab doing some experiments on genes. Due to curiosity he approached me. I explained to him the relevant principles and operations of the experiment in detail, while he was fascinated and excited. When I finally saw the excited smile on his face, I smiled uncontrollably too.

"But I made a mistake later. One afternoon he asked to go out, and I readily agreed. But he didn't come back though it was getting dark. I went out anxiously to look for him, but there was no sign of him. I cried out worriedly, but then an envelope floated over and landed in my hand. I opened it and it was from the cat. He said he was in a capsule-shaped building, which was huge. In addition to another bunch of creatures like birds, fishes, sheep and so on, all that was left were some weirdly-shaped robots. He also told me that he found the place very eerie because all the creatures he saw would cry out 'Help' from time to time. There were some strange graffiti on the walls, probably shaped like ribonucleotides, but they really couldn't make out what they meant. The only useful clue he has so far is that when a robot passed him, he was repeating 'Genetic weapon! Genetic weapon!'. My guess is that the lab might use these animals' unique genes to build a genetic weapon that's almost invincible. He said at the end that he would really like to escape, but that seemed unlikely.

"I'm so sorry I let him go out like that! And I didn't get him back in time! I don't know how he is now! I only wish he were with me now! Oh, no! He's got unique genes. It can't get lost like that!" He could no longer control himself, closed his diary book, and sank into a sob.

The others also heaved sighs and sulked.

"Don't be sad, Sir." William patted him on the shoulder, "We, too, are sorry for your loss of a precious cat."

"Well, it is worth pointing out that you will have to go through that distance to reach the 'capsule' building that the cat described at last -- and there will be checkpoints along the way that will charge your energy core. That's what your little robots told me, so I know what you are doing."

"We will help you find that cat!" The party answered firmly with one voice.

Thomson's eyes sparkled. "Really? Even if the road is full of unknown, you will not hold back?"

"Never hold back!" Said William again, in a strong, sonorous voice, so loud that the whole tree house trembled.

"Thank you very much, then!" The shorthair cat was lying on the ground, saluting excitedly. Ranran helped him to his feet.

"You're welcome. That's what we ought to do." She gave a sweet smile, "Please don't be sad. I'm sure we'll save the cat for you!" She kissed Thomson gently on his tear-stained cheek.

"This is the best! It is my lifetime joy to meet such kind people like you!" Thomson stood up and took William's hand excitedly. He laughed, too.

Photon said, "We have the map. But please let us know if you know anything about the journey."