Yi Chen stared at the clown-like girl before him. At the same time, he had Little Grape activate her global vision, staying alert for any possible Nightmare ambush.
"Who are you?"
The girl lightly pressed the tip of her nose. "Call me Catherine."
"Are you the source, or merely an ordinary derivative?"
"Well~ I can't tell you that yet. Of course, once we become familiar enough with each other, I might consider secretly telling you this little secret, hehe!"
Because the girl was wearing exaggerated black smiling-face makeup, she seemed to be smiling at all times.
"Was the purpose of calling me here just to show off the results of your 'invasion'? You combined Nightmare Substance with meat products people eat every day, thereby infecting the entire city."
"No... No!"
Catherine hurriedly denied it, planting her feet in black-and-white stockings on the ground as she walked and explained.
"'Infection' isn't quite the right word. 'Implantation' would be more appropriate, because what we released is extremely special and very different from ordinary pathogens.
"By the way, William! Do you know what the most stubborn thing inside humans—or any life-form capable of thought—is?"
"I don't." Yi Chen gave up and waited for the answer, too lazy to think.
Catherine slowly walked over and reached out to touch Yi Chen's forehead, but he stepped back and opened up the distance.
Having no choice, she pointed at her own forehead.
"An idea~ Once an idea is implanted in someone's mind, it's not only difficult to detect, but basically impossible to escape.
"This idea will slowly merge into them after implantation until it becomes an indispensable part of the individual, affecting their most basic habits and even replacing their original personality.
"No inspection device can detect it, and all conventional methods are ineffective.
"This is