At last the performance came to an end. The spectators bid a reluctant farewell, as well as some disappointment, as if the most professional explorers had failed to find the treasure.

"I didn't expect Maria's debut to be such an amazing one. And this is her improvised work! You can imagine how good the work she had prepared before! It's a pity the score is lost." Sighed a member of the spectators as they walked out the door.

The party stood silently on the stage, watching the spectators leave. "Thank you very much, William." Maria hugged him, letting tears of joy and gratitude paint her face.

"It's all right. We've done the Director Mr Wilson a great favor. Besides, you've got two apprentices. Uh-huh." William winked at Ben and the little boy.

"I'm sorry, Ms Maria, but we can't stay. We have to move on. After all, we have to go back to our own universe." As Ranran said, she turned on the computer, looked at the map, and shouted with surprise and delight, "The next station is... Uncle Sam's Garage 95!"

"Really?" William could hardly believe his ears. He looked again, and it was true. "Excellent, miss! We're on our way to your father's!"

"Wow, what a coincidence! I am going home, too! How about going together?" Maria asked the others cheerfully.

William merely winked, had a friendly smile, and said nothing.

"There are Checkpoint 5 and 6 here," Natalie said as they collected another 5% of their energy on the way.

Soon, in the distance, they could see a huge gray concrete building rising above the mountains, like a mighty giant. The exterior walls were icy gray, but dotted with red or orange graffiti depicting engines, gearboxes, suspension systems, tires and so on. The gray walls were covered with windows like pieces on a chessboard. Two large iron doors stood at the entrance, peering around anxiously as if waiting for the next customer to arrive. The number "95" was emblazoned on the roof. When night fell, it was easy to catch its light even from kilometers away.

They walked to the doors. Photon watched attentively, like detectives at a crime scene searching for crucial clues, and could not help exclaiming.

"This is your father's garage?" William looked at a graffito of an engine and asked Maria, "Nice graffito. This is a typical V8 three-turbocharged engine. The smaller one is the electric turbine." He said, pointing to a swirling device above the flywheel.

"Expert!" This was a surprise to Maria.

"Why don't you leave the score with your father?" Ranran asked in bewilderment.

"There's never anything in here that's anything other than necessities." Maria shrugged and sighed, "For example, if I have wrenches, screwdrivers and batteries, I will put them in numbered storage bins; and if I get a piano, I won't hesitate to load it up and drive it hundreds of kilometers to my home. There, there it is."

"Aren't you bothered to do that?" Natalie was still full of doubts.

"Why is that troublesome? Isn't it troublesome to look for something after you put it carelessly? Let's hurry in, and you'll see."

She stepped forward and the doors opened.

"Maria, is that you?" A strong, deep voice came from within.

"It's me, Dad! And some guests!"

Hearing this, a strong man rushed out from the inside. He had a forest-like beard and shining blue eyes. He was wearing a blue cap, a pair of black leather shoes, and a blue and yellow halter overalls. But that didn't hide the striped T-shirt inside. William could see that he had not had time to put the spanner in the pocket of his overalls before he ran out to meet them.

"I'm Sam. Nice to meet you." He said, smiling ingeniously, taking a step forward, and giving William a firm handshake.

"Nice to meet you, Uncle Sam." William introduced the others.

"Honey, I heard you had a great debut?" Sam asked.

"Yes, Dad! I also had two apprentices! And, thanks to their help, or the debut would have been delayed for a month!"

"Oh, really? Look, if it weren't for your carelessness to forget to go home to take the music score, will you need to trouble someone else? But as the saying goes, 'Bad luck may turn out to be a blessing in disguise', it was your carelessness that made the performance so great. You must thank these kind-hearted people! Well, you'd better come in and have a seat. One of the engines is not ready yet." He started inside, holding the spanner in his hand, and the others followed.

As they walked inside, William took in the sights of the hundreds of orderly storage boxes that lined the high white walls. Each drawer of boxes had been numbered six digits so that its contents could be sorted. After turning a corner, they saw four rooms at once and entered the first. In the spacious room, a dozen engines sat quietly on a sheet of steel, waiting to give strong pulses again. In a nearby room, gearboxes of different models were neatly stacked, forming a hill. The third room was a storage room for other components, such as floor-type clutches, brakes, and gas pedals, multipurpose steering wheels with shifting paddles, various types of batteries, as well as various doors, hoods, and car shells. The last room was where the smaller parts and common tools were stored. Sam often placed wires, buttons, brake calipers or hammers, spanners, multimeters, etc.

From the last room they entered a long corridor. Natalie was surprised to find hundreds of sports cars of various shapes neatly parked on both sides of the corridor. Some had slender heads, while some had stout tails; some had their exhaust pipes directly arranged on the hood, while some had them extended to the rear; some had rear wheels much stronger than the front ones, while some had similar tire sizes. She stopped in front of a long-headed red sports car, looked admiringly at its sleek back, touched the exhaust pipes behind the front wheels with her tires, approached it, looked up at its luxurious interior, and finally sighed, "Oh, I'm dwarfed. It could be a scooter while I would only be a racetrack imp."

"That's not right." Photon comforted her, "You may think you don't like roads as much as tracks, but you can go on roads. And it's not that you can't afford to be comfortable and luxurious."

"You built all these cars by hand?" William asked Sam, gazing admiringly at the priceless treasures.

"That's right."

"Great! These aren't just cars. I think they have become pieces of art under your skillful hands."

"Thank you! But I prefer to keep them." Sam patted a black sports car and said, "It's just some carbon fiber, metal and ceramic parts that have been cleverly worked to create it. The cost of these accessories is not very high, but it is very valuable."

William saw another purple sports car. He lifted the hood of the car in the front, and what he saw was a thick and powerful heart. On the white cylinder head there were words engraved with gold "6.4T V8". A nameplate under the hood had two parameters, "704 Ps 1,200 Nm."

"It must be a gasoline engine," He thought to himself.

"No, it's a diesel engine." After William questioned Sam, he replied.

"Wow! Diesel engines have high powers?"

"That's because I used a V-shaped layout and a twin turbine plus supercharger. There is also a lower-powered version of this engine because I have eliminated the supercharger. It produces 512 metric horsepower and 1,000 Nm."

"I also have a special passion for compression ignition engines, because I just love them." William said.

"Me too, except that's because I'm lazy and I'm not very good at electrification, so I never want to maintain cumbersome ignition systems, which gives me headaches at the sight of ignition coils and spark plugs. Instead, I prefer compression ignition engines because they are strong enough to allow me to squeeze power constantly, and their simple constructions ensure the reliability and longevity. You know, those high-powered gasoline engines are expensive to maintain, but diesel engines are not. The money is mostly spent on maintenance of the ignition system."

They went on inside. "However, I have also built a few gasoline sports cars. But the number is too small, only seven. And given that we all use biofuels these days, they're not as different in performance as fossil fuels. Look at this. This is my first gasoline sports car, Thunderbolt."

Sam pulled off a piece of cloth and a green sports car unfolded in front of them. Its low figure was like that of a cheetah waiting to attack, and its short head was round but extremely sharp. Behind the cockpit was the engine compartment, which took up about 60% of the length of the car. The four green tires were wide and stout, and the rear wheels were two inches larger than the front ones. Four exhaust pipes protruded from the diffuser at the bottom, and the nozzles were electroplated into blue. The large tail wing not only provided downforce, but also retracted itself at speeds below 150km/h to reduce drag. Lifting the lightweight carbon fiber hood, William saw a bright black heart. The parameters were "6.5 V12 1,050 Ps 1,400 Nm".

Sam said, "This is the only naturally aspired gasoline engine I have. Tachometer gauge is 10,000 RPM, while speedometer gauge is 400 km/h. And it's the only one I have right now. I don't necessarily show ordinary guests it when they come to visit. You've really helped my daughter a lot. I can't thank you enough. So if you want to see it, I can start it for you right now. To tell you the truth, this heart hasn't been beating for a year, and the last time was when I was refitting it."

Without waiting for anyone to respond, he opened the lightweight butterfly door, sat inside, and pressed the red start button.

The heart, flowing with clear blood, growled low. But when Sam stepped on the gas pedal, it was a different story. The corridor was filled with high-pitched shrieks as the tachometer hand approached the red line.

Sam was actually trying to take it to the warehouse where he refitted his new engines, yet he made an excuse and said,

"You go ahead. Turn left at the end of the corridor, turn right at the third fork, and go straight ahead. When you see the 'Testing Room', go in. There are the engines I've just been refitting. Diesel engines, no doubt. I have something else to do. I'll be with you in a few minutes. Excuse me."

The party left, but William asked him another question, "Uncle Sam, do you know anything about Capsule Laboratory?"

"Oh, the one where the gene-edited cat got trapped?" Sam's eyes sparkled.

"Yes, I received this note to consult you." As William spoke, he pulled out the note he had received when he left the windowless building,

Codon insertion position: DNA#18~#19

Codon first digit: G

Codon medium digit:?

Codon last digit:?

Sam took and saw it. "You guys go ahead." He said, "I know this stuff. I'll tell you when I find you."

"All right." They left ahead of Sam and headed for the testing room.

The fast-moving party had no time to pay attention to Uncle Sam's serious and careless work on the walls beside them, and had no energy to admire the sports cars parked beside the walls after turning a corner. All they did was run on and on, letting the wind blow in their faces. Ranran's black hair floated up, dancing happily in the wind.

Finally, the words "Testing Room" caught their eyes. "Here we are!" As soon as he got to the door, William opened the door and walked in, only to find Thunderbolt again.

The butterfly door opened again. The stout, bearded uncle stepped down, smiled, and said, "You underestimated the speed of Thunderbolt."