With the muffled roar of eight 1,800-horsepower blue-green algae diesel engines, two huge black figures darted through the tunnel and shot into the sky at the exit.

"It's just sunset," Said Plane 1, continuing its rapid climb. A minute later, they had risen to a height of 1,000 meters.

"Turn on all cameras." Said Plane 2.

"Roger that." Answered Plane 1.

They looked down. The huge capsule-shaped building was painted a horrible, cold black, and a patrol of hundreds of robots was just outside the gate. The mother star gradually gathered its bright blue light, and the deep night fell bit by bit. On the ground, occasionally there were crickets singing and fireflies dancing and, of course, the owls hunting. In the distance, the wavy contours of the mountains were set against the stars. The clear tinkling sound of running water was swallowed up by the quiet night. And in the cold building, in a large, narrow room, hundreds of poor animals looked out of the window from time to time with misty eyes, as if praying to the stars for just one more second of life.

"Altitude 8,000 meters, speed 465 km/h, heading 45 degrees." Plane 2 said to the others in the tunnel.

"Good. How far are you from the lab?" Photon asked.

"It's about three kilometers east of us." Replied Plane 1.

"You can turn. Look at the density of patrols on the ground first." William said.

"Roger that." Plane 1 rolled an angle to the right, pulled up the elevator and turned right. Plane 2 was now behind him on the left and also turned a corner.

High up in the air came a fierce wind, but Black Ghost did not fear. The perfect coating made them real ghosts in the night sky. It was almost impossible to see them with the naked eye.

They noticed that by this time the number of robots on the ground was increasing. The robots eventually joined up in a long procession and marched off. A mysterious murmur drifted faintly into their ears.

Hiding high in the sky, the ghosts were extremely cautious and careful, trying to avoid being detected by the robots on the ground while trying to search for their target. The good news was that they were close to getting the job done.

But just then a thick cloud swept past and quickly surrounded them.

"Damn it!" Cried Plane 1 angrily.

"Never mind. Don't be angry." Ranran's sweet voice came over the radio, "We can do it again."

That seemed to be the only way. After flying out of the clouds, they continued to circle, desperately searching for their target.

"You are right. The patrols are increasing, but there are only a few of them." Plane 2 looked down through a camera at the ant-like shadows.

The spider radioed them to keep circling, and he was going to send some more spiders to the same computer.

"What are you going to do?" Asked William, puzzled.

"You'll soon find out." The spider smiled mysteriously again.

Black Ghost sneaked under the stars and circled Capsule Laboratory half a circle. With the cover of clouds -- the patrols could not see them unless they were flying very low -- they were back to where they had started.

"Very safe," Said Plane 2.

Meanwhile, in the secret tunnel, the little spiders had already turned on the computer, methodically operating.

"You can descend to 6,000 meters." The spider told Plane 1 over the radio.

So the two reconnaissance planes slowly lost height, and below, the endless grassland was more clearly. At this point, if he walked on the ground, one would be able to enjoy the unique cricket symphony. Unfortunately, for Black Ghost, the roar of the engines obscured everything.

"Wait, get into the clouds!" Plane 2 swerved to the upper left. Plane 1 was at a loss and had to follow.

The air around them became extremely heavy in an instant. A sudden surge of power came over them as if several layers of heavy packages were wrapped around them. Plane 1 gradually felt a loss of engine power, the wing roots slightly deformed, and camera images began to blur.

"I see you," Said a voice hoarse and more distinct.

Black Ghost bombers suddenly felt a gust of air in their faces, causing their wings to shake violently. Then an eerie cloud of black gas appeared. It slowly flowed and gathered until it turned into a giant eye.

"Come out!" The eye looked about greedily, like a hungry cheetah searching the jungle for a good dinner.

"No way!" Plane 1 thought angrily to himself.

The eye gave an angry groan, and was blown away by a swift gust of air.

Flying out of the clouds, the spy planes saw that the robots on the ground had now gathered in a large group. The leader at the head of the line had stopped his patrol and was looking up into the air.

"There must be something up there." He said emphatically.

"That's impossible." One of the robots said to the leader at the front, "You must be imagining. As it happens, it's time for us to leave work, and I only have 5% battery left. So I think we should take a three-hour break to charge our batteries before we patrol again."

"Agree! Agree! Agree!" The other robots shouted in unison.

"Objection!" Cried the leader, in a blaze of anger, "Have you seen any sense of organization in your two hours of free movement? Walk for another half an hour!" And with that he strode on.

The robots were full of complaints. "No way, 5% will only last ten minutes at most!" One of the robots complained.

"Yeah, and it's getting colder and colder now! If we continue like this, we'll all be down in five minutes if we don't get back to the lab soon!" Snapped the robot next to him.

The night was quiet except for the roar of the engines of the two planes. "Look at those robots on patrol. Why are they slowing down?" Asked Plane 1.

"I'm not sure." Plane 2 replied helplessly, shaking his fuselage, "We haven't had it the last time we were here... Oh, snow!" He could clearly see thousands of white elves in the sky dancing to the ground in the wind.

It turned out that this was because the little spiders in the secret tunnel had turned on a switch. Hundreds of tons of liquid nitrogen shot rapidly from a network of nozzles indoor and outdoor, causing the surrounding temperature to drop dramatically, which was why the snow was falling. The wind seemed so powerful that within a few minutes, icicles were glittering everywhere in the planes' sight.

The liquid nitrogen spread like lightning, making the robots shiver. The batteries were fading fast. Three minutes later, they all fell to the ground, unable to move again. Inside the lab, robots were not immune to the biting cold.

"Hee-hee. They will have three hours for a good rest!" The spider robot sneered.

"What is this? Why don't they move?" Plane 1 saw that the "ants" suddenly stopped moving, puzzled.

"They're out of power, man. You can spy at low altitudes!" Ranran shouted excitedly.

"Really? Are you sure?"

"You bet!" Natalie jumped up and shouted excitedly.

Two spy planes adjusted attitude, like two black lightning, rapidly diving down. "Altitude 500 meters, speed 620 km/h, heading 135 degrees." Plane 1 radioed.

"Slow down, but don't stall." Said William, "How much fuel have you got?"

"That's probably enough for us to fly another two thousand kilometers." Plane 2 caught a glimpse of the fuel indicator and answered him.

"Do it as soon as possible." Natalie said.

"Roger that." They had now returned to the position again from which they had begun their spy. Plane 1 maneuvered quickly, reducing speed to 250 km/h and altitude to 300 m.

The large black capsule was clearly visible to them again. From the cameras' image, the party had a full view of the details on the wall. Every few meters there were sharp scratches painted bright red, interspersed with symbols that looked like DNA models.

"That's probably a record of their brutality." Ranran whispered to William.

"How can such sins be forgiven!" Again he beat his breast angrily.

Eight 1,800-horsepower engines roared furiously, pulling the ghosts through the night. They caught glimpses of fireflies perched gently on the dark walls of the laboratory, motionless and watching.

For an instant there was a profound silence. William closed his eyes, and he heard his burning heart cry. Blood was its tears.

Suddenly, two green doors entered the camera frame. The spider robot's sharp eyes immediately picked up the word "Exit" next to the door. "Hey! That's the goal!" He radioed hurriedly to the two spy planes.

"Yes, we found our target." Plane 1 smiled with relief. By then, he had marked the coordinates on his radar.

"The terrain around here is very good, very flat. Once the animals are on board, we can evacuate quickly." Said Plane 2, looking down at the rapidly receding grass.

The planes roared with joy and adjusted their postures. When the two huge black figures reappeared in front of the party, they rushed toward them, laughing together, and threw themselves on top of them.

"Yeah!" They took turns clapping. Cheerful laughter echoed in the secret tunnel.

Two spy planes were out of breath.

"Come and have a rest." Said the spider robot to Black Ghost.