After the initial reconnaissance, I discovered that the northern battlefield offered the most open terrain, and it was where Li Yuanhao's main forces were stationed. I had attempted to break through there earlier, carrying the "Wu" banner, so the rebels would naturally assume it was our designated breakthrough point. Although the first attempt failed, logically, attempting it again here was reasonable, as we had nearly succeeded.
"But this map of yours isn't precise enough," I said, pointing to the sketch. "I need a topography map of the area outside the north gate, as accurate as possible. Bingbing, you can measure distances, and Xiao Nu, you're good at drawing. You two go to the north gate wall and draw me a map of the outside."
The two received the order and headed for the north gate. I inspected the cannons. After the violent jolting of the earlier charge, some of their structures had loosened, including nuts and bolts. The accompanying engineers were giving the cannons a "physical check-up" to ensure they were in optimal firing condition. I asked them how long it would take to finish. The engineer said it would be a while. The wrenches they held were clearly the latest models, crafted under Dai Lu's guidance, identical to modern wrenches, just without any nameplates or trademarks.
As I was about to check the cannonballs again, Zheng Baobao rode over, with a bird that looked like a hawk perched on her arm. It was a bit small, even smaller than a pigeon.
"Is this your pet?" I asked with a smile.
Zheng Baobao was quite serious. "This is an eagle-pigeon. Originally, only royalty could train them. Now, with the war, the royal eagle-pigeons are all used for transmitting intelligence."
I thought to myself that the court of the underworld must have some method of rapid information transfer.
Baobao pulled a strip of paper from a small aluminum tube attached to the eagle-pigeon's leg and unfolded it. She looked at it. "Hmm, it's for you, as expected."
She handed me the strip of paper. I looked at it and handed it back, unable to decipher it due to my own hurried handwriting.
"What does it say?" I asked.
"His Majesty is inquiring when you plan to make your move and how you intend to fight."
So, it was a letter from outside the city.
But I couldn't send my operational plan back to the King of Hell via eagle-pigeon. No matter which direction this little creature flew out of the city, it would be exposed to the rebel forces. If there were any skilled archers among the rebels, or someone incredibly lucky, who shot it down, my tactics would be ruined!
In fact, could this little thing have flown in because the rebels deliberately released it? Thinking this, I suddenly had an idea!
"Baobao, is it possible for your eagle-pigeons to be killed by the enemy?" I asked.
"Why wouldn't it be possible? I could shoot one down," Zheng Baobao replied.
"Then sending messages with them is quite dangerous."
"We can release three at once. If one is shot down, the others can get through," Zheng Baobao said.
I nodded, then thought, "These things are quite precious, aren't they?"
"They're alright. We only have over seventy left in the city now."
Precious? They're hardly precious. There are fewer of them than cannons. We only brought fifty cannons with us.
"Lend me three. I need to send a message to His Majesty," I said.
Zheng Baobao dismounted and took out three small rolled-up paper scrolls from her embrace. "Alright, you speak, and I'll write. But it can only be twenty characters."
"That's enough. You write: At the sound of three cannon shots at Geng hour, the entire army will break through the south gate. Please be ready to receive us." I counted on my fingers, including punctuation, it was exactly twenty characters. No need to waste resources.
"The south gate? Are you sure?" Zheng Baobao asked, frowning.
"No, the north gate. This is a diversion."
"But..."
"Don't worry about it, just listen to me," I said with a smile.
Zheng Baobao quickly copied the other two scrolls and handed them to a palace servant carrying a cage. The servant took three eagle-pigeons from the cage, rolled the paper strips into the small aluminum tubes on their legs, and headed towards the city wall.
I followed him up to the city wall, eager to witness the operation of carrier pigeons, something I had never seen in the mortal realm.
The palace servant released the three eagle-pigeons simultaneously. These birds were clearly well-trained. Knowing there were enemy forces below, they immediately ascended into the sky. They flew to an altitude of about a hundred meters before heading in the direction of Li Yuanhao's camp. Furthermore, the three eagle-pigeons flew at different altitudes but were in a straight line vertically. This way, if the enemy fired, the lowest one would provide cover for the other two.