Three days later.
After Xia Xu's "corrections," the plot got back on track.
Although Yu Zhengqing had spent the first two days desperately hiding after being released from the De City branch, by the third day, he finally could not resist returning to the alley where he had lost the serum. There, he duly came face-to-face with Yao Fu, who was "luring the snake out of its hole."
After a brief exchange of blows, just as the plot synopsis described, the two men, each with something he needed, hit it off immediately. After a day of preparation, they headed for De City's western outskirts at night.
As for how Xia Xu knew all this in such detail, it was naturally because the Special Department's people were monitoring and tailing the pair around the clock.
Their combat capabilities were another matter, but when it came to tracking and surveillance, the Special Department had plenty of professionals, as well as no shortage of high-tech surveillance and listening equipment.
Although the Bat-Men all had good hearing, and Yao Fu even possessed echolocation, echolocation required emitting ultrasonic waves to actively scan the surroundings. No normal person could possibly keep that running all the time.
Leaving aside how much effort it took to produce ultrasound and process the information in the brain, the sheer amount of background noise they heard when concentrating was enough to make them suffer. After all, even ordinary people became irritable and dizzy in noisy surroundings.
Moreover, the Special Department's people had an inherent advantage: they could freely access all kinds of existing surveillance facilities. Combined with the miniature devices they planted themselves and methods such as posing as passersby, tracking these two while remaining hidden was almost too easy.
"Call in some more people. Let's go join the fun too.