Accompanied by the rapid spinning of the propellers, the drone slowly ascended from the grassland, reaching a height of about ten meters before coming to a stop there.
Li Yu held the remote control in his hands, gently pushed the joystick, and tested whether the drone's ascent and horizontal movement functions were working properly.
The signal transmission between the drone and the remote control didn't rely on the internet, but through its own antenna, which was greatly affected by electromagnetic interference and environmental obstacles within the city, shortening the effective transmission distance significantly.
Take Li Yu's DJI Mini 3 Pro as an example, under the FCC standards, the official range in strong interference flight conditions was approximately 1.5 to 3 kilometers.
However, in the suburbs and seaside, this distance could be extended to 7 to 12 kilometers.
As for Green Field, there was no Wi-Fi, Bluetooth, or other signals to compete with the drone for bandwidth, making it the perfect flying environment.
Of course, there were drawbacks. Without the assistance of GPS, it was difficult for a drone to achieve precise hovering, and functions such as flight route planning were also unusable, greatly increasing the risk of crashing.
But Li Yu had no choice at the moment, he turned off the drone's obstacle avoidance feature, and made the drone ascend another hundred meters to ensure it wouldn't be easily spotted by people below, then he controlled it to fly towards the castle.
At night, the occasional pleasant evening breeze made the drone sway and drift in the air. Each time this happened, Li Yu had to correct the drone's direction by manipulating the controls.
Fortunately, even though the visual system struggled with positioning due to the darkness and the loss of GPS, the drone still offered a basic attitude mode to help stabilize itself, significantly reducing the risk of crashing.
Eventually, Li Yu managed to fly the drone over the high walls of Teacup Castle without alarming the army outside or alerting anyone inside of the uninvited guest's arrival.
Even if someone happened to look up, they would probably only think it was a strange bird passing high overhead.
Li Yu scrutinized the soldiers on the city walls through the real-time images transmitted back by the drone's camera.
Miss Rabbit was by his side, tasked with identifying Alfred from among them.
As Li Yu adjusted the zoom camera equipped on the drone, faces were pulled in close and magnified, prompting Ireya to exclaim in amazement.
By now, Miss Rabbit had also become somewhat numb to the spectacle.
Earlier that night, Li Yu had awoken the Ancient Spirit sleeping within her necklace and summoned the metallic divine bird, capable of flying and burrowing through Earth. Using the divine bird's eyes, he captured a comprehensive view of the surroundings.
The girl was in constant shock, so much so that if Li Yu suddenly shouted "Here goes the Great Sage!" and then rode on a cloud, flipping through eighty thousand miles, Miss Rabbit would probably not be too surprised.
She would at most shout from below, "Great Sage, please withdraw your powers quickly!"
Not far away, Half-Face was no better off than her. When the drone took off, Jude seemed to have his soul escape along with it.
He stood still, gazing intently at the small black dot in the sky, unmoving.
Like a human child seeing an excavator for the first time, he was unable to look away, muttering incessantly, "There must be a spirit in there! Yes, there must be a spirit!!!" and such nonsense.
Li Yu controlled the drone to circle above the castle, yet he couldn't find any trace of the old knight.
Yilei volunteered eagerly, saying she could lead the way into the stone castle, but Li Yu thought about it and decided to abandon the idea.
Once inside the stone castle, due to the obstruction of the thick stone walls, the signal would undoubtedly worsen, the risk of crashing would increase, and in a cramped and narrow space, the drone would struggle to dodge any unexpected incidents.
So, in the end, Li Yu opted to push the joystick, commanding the drone to descend in front of a soldier.
When it dropped to about twenty meters, the noise of the four pairs of propellers woke the dozing soldier.
He rubbed his eyes and looked in the direction of the sound, then paused in astonishment.
To allow him a better look at the flying machine, Li Yu further lowered the drone's altitude.
As a result, the guy let out a shriek, tossed his spear and shield casually to the ground, and decisively knocked off early from work, without a care as to where he fled.
Li Yu had no choice but to direct the flying machine to another soldier standing on the city walls.
This one was much braver, drawing his weapon and waving it around as if trying to scare away the little wingless creature that could fly.
Li Yu was thus forced to watch his combat skills for quite a while.
Fortunately, when he realized that he couldn't reach the drone with his attacks, he finally made the right choice, remaining guarded while calling over a comrade to alert the people inside the stone castle.
Just as Li Yu was beginning to lower his guard, an arrow shot out from nowhere, heading straight for the unmanned flying machine!
Taken off guard, Li Yu had no time to react. It was a gust of late wind that saved him, blowing the drone aside just enough to avoid the lethal arrow.
Without hesitation, he immediately raised the altitude of the drone and maneuvered it erratically in the air, so the following arrows posed no threat to the machine.
After waiting a while, an old man clad in Armour, looking around fifty or sixty years old, emerged from the castle and climbed onto the stone wall.
He squinted, scrutinizing the object in the sky.
And Li Yu was also observing him through the drone's camera.
The newcomer was tall and well-built, with a determined look in his eyes. His face, though wrinkled, did not show signs of frailty. His silver hair was meticulously groomed, and his Armor was polished clean.
But unlike the splendid suits worn by many Nobles to showcase their valor, his Armour clearly had seen better days. On closer inspection, there were many dents, faithfully recording his past brutal battles, and on his right arm, a Rabbit crest revealed the family he served loyally.
In his hands, he held a yew longbow nearly two meters long.
Taking a Battle Arrow from the hands of an Attendant, the old Knight nocked an arrow to his longbow, its dagger-like head glinting coldly in the night.
Ultimately, he didn't release the arrow.
After placing his longbow down again, he gestured to the surrounding archers to lower their weapons as well.
They looked at each other and eventually complied.
Li Yu turned to look at Ireya, who nodded to him, "That is Alfred, my Guardian Knight."
Hearing this, Li Yu controlled the DJI Mini 3 Pro, carrying the Ruby and Ireya's handwritten letter, to descend.