"That's a good position," Said Plane 1 breathlessly and excitedly, stopping his engines, "very good for take-off on site. But I don't know where we're going."

"Have you ever heard of a shorthair cat named Thomson who lives in a tree house?" Natalie asked.

"The name is familiar. I think you once mentioned him. Er, did he develop a gene-edited cat that can resist a terminal disease?" Plane 2 shouted excitedly.

"Yes, that's him! The cat is in there, too. All we need to do now is to seize these three hours, get all the trapped animals out and fly to him!" Ranran said majestically.

"It's all right, don't worry. He's seen us, so there's no problem." Black Ghost was still not reassured, so Photon advised. They finally agreed to Ranran's idea.

"So let's do it now!" William held out his hand as the others formed a large circle and shouted in unison, "Come on!"

The voices were like a sharp sword that cut through the thick layers of earth and rose into the sky.

They split into two teams: Photon and Black Ghost, all who had to do was to head for the secret exit, wait patiently for the trapped animals to board the planes, and then leave; the rest of the party formed another team. For them, the task was to sneak into the laboratory, find the room where the animals were trapped, quickly and smoothly lead them safely to the secret exit, escape through the secret tunnel and, at the same time, trigger the bomb to blow up the laboratory. The spider robot told the others that this bomb was Uncle Sam and his secret.

After running out of the tunnel, Photon, led by Black Ghost bombers, flew for ten minutes and landed smoothly in front of the secret exit. Sure enough, he could clearly see the graffiti that had just appeared in the camera frame. The glare of the stars on the blood stains made them clearer and more glaring than ever, so that the hearts of the three planes were again burning with rage.

"It was a huge mistake that this lab even existed!" Shouted Photon.

"So we're going to destroy it." Plane 2 took his words.

"Destroy it?"

"Yes, we have planted bombs in various areas of the lab, and the trigger is in the secret tunnel."

In fact, they could have seen the trigger when they came. But because it was so small and on top of the tunnel, it was impossible to keep their attentions on the roof.

The liquid nitrogen had spread far away, and the temperature was rising. A breeze blew, and Photon's propeller rotated gently. Then they heard, in the hush of the night, the occasional cricket symphony; fireflies were taking part in a grand dance happily in the distant woods. An owl flew overhead, fluttering its wings and hooting softly. But then it didn't fly any further off -- instead, it landed lightly and quietly on the roof of the laboratory, looked at the strange, ugly, large black shape at its feet, shook its head, and sighed. As it was about to take off, it was stopped by Photon that had been watching and landed in front of his landing gear.

"Your relatives are in there, I suppose? A friend? Or somebody else important to you?" Asked Photon softly.

"Yes, there are my children in it." Sobbed the owl, "Because of the unusual gene LCTUP-43S, their nervous systems are much more sensitive than the average owls', which will undoubtedly benefit their life. It is a pity that bad luck has befallen them at a time when they should have been happy!"

"What do you mean?" Asked Plane 2 in surprise.

"They were caught when playing!" The owl could stand it no longer and let the tears flow down. The night sky was filled with sobs of grief. The grass in the distance seemed to understand, so that their tips were glistening with dewdrops. The wind became very cold.

"Don't worry, you'll see your children soon." Photon gently wiped a tear from the owl's eyes with his propeller.

"Why do you say that?" It raised its head and looked at him.

"There are our partners in there, too, and they want to free all the animals in captivity."

"What? Is it true? That would be wonderful!" The owl changed its sorrow into joy, but worried, "But the security system here is so perfect..."

"It doesn't matter. We've taken all the robots out of action. Plus, we'll take the animals and fly away. The lab can't shoot planes down." Plane 1 was patting his chest, saying confidently.

"Great! Come back to your mom's arms, my children!" Hooted the owl excitedly.

Meanwhile, the other team didn't slow down. They entered the lab through the gate and then saw a complete map on the wall of a corridor.

"Look, this is the electrical room." The spider robot climbed the wall and pointed its paw at the block numbered 327, "We'd better go here first, because then..." He suddenly hesitated for a few seconds, but then added, "Well, that should make it easier for us to finish the task."

The party hurtling down the corridor paid no attention to the drooping, motionless robots on either side. The little spiders went on a killing spree. Every time they saw a robot, they sprayed some liquid. As a result, they never saw a single whole robot again.

They walked to an elevator. William pressed the button and the door opened. But when they had just chosen the floor and pressed the button to close the door, all the lights in the elevator suddenly went out.

"Aargh!" Ranran screamed in horror, yet soon everyone was suffocated by an invisible hand.

The hand left the others and clung to William's neck. He heard a voice say, laughing maliciously,

"Take things as they come. You shall not go out again!"

"No... Well, er... We'll be able to get out... It is you, instead, who should think about -- er... That how long your own lab can survive... Er... Let me go, or I'll... Er... Be rude... !" William gasped hard, involuntarily forcing out the words. He was not sure why he said these.

He suddenly growled furiously, like a hungry lion. The hand seemed to be instantly frightened by him, disappearing as fast as a pray. The lights came back on.

"Are you all right?" Ranran pressed her red lips gently to his face and kissed him.

"I'm fine, Ranran." He replied, thinking himself wide awake.

"Oh, you must be safe."

He cupped her chin gently in his hands, "It's all right, I will. We can definitely go back to our universe."

"Ding!" The elevator reached the floor and opened the door. They caught sight of the huge number "327" at the end of the corridor and darted toward it like lightning.

"You are about to have a taste of being pushed around." The spider twisted the handle and ran into the darkness.

The only light around was a huge circuit board. With the help of those diodes above, they found the character "CAM".

"Look, this is the master switch that controls the cameras. We just have to pull it down, and it will cause..." The spider winked at William.

"Oh, cause the monitoring system to crash!" He replied.

"Bingo!" Quickly, the spider pulled the switch. The red lights on every camera in the lab -- indicating power was on -- went off.

"Yeah!" They cheered and capered.

"Now we can confidently and recklessly search the room where animals are trapped." As he said, the spider went out, found the map in the corridor and studied it carefully.

"The experimental area... The preparation room... Yes, yes, that's it! Room 408. We can take the elevator up." They hurried into the car, took the elevator, and went in search of the poor guys.

The elevator doors opened. Led by the spider, they trotted down the long, narrow corridors, the wind whistling in their ears. They didn't pay much attention to the nucleotide markers on the walls or "genetic weapon" that appeared occasionally. The only thing that resonated in their ears now, though they had never heard it, was the mournful cries of the poor animals in Room 408. All that flashed through their eyes like a movie was the robots pulling the trigger of a laser gun and the spatter of blood. All the minds and hearts were filled with a sonorous, powerful, resounding words,

"We shall be free!"

For an instant, William felt that the picture in front of him froze. Then everything around him sped away in all directions, disappearing into the darkness behind. What came into view were animals standing neatly in two rows. The monkey painfully looked at his feet, and the oriole bird kept singing sadly; the giraffe sticked out its tongue and licked its bloody wound, while the cat looked out the window at the clear night sky. The glittering tears in the cat's eyes kept spinning, reflecting the brilliant light of millions of stars like diamonds.

Suddenly he came back to himself, and was surprised to find that he had found himself, like the others, at the door without knowing it. He saw a few lines on the left,

F (x) = x4 (sin x - cos x + log2,135x · tan x), [F (2,135π)] ' = ?

"Gosh, this function has a long analytic formula! How many lifetimes will it take to work out, huh?" Photon stared blankly, scratching his head.

William, with just a smile on his lips, calmly walked to the button on the right and pressed "0".

"Whatever F (2,135π) is, it must be a constant." He smiled, "And the derivative of a constant is always 0."

The door opened.