"Wait." The other party hurriedly said, looking at Luo Zheng with an increasingly wary eye, his face bitter, and continued, "According to my investigation, the cleaning staff are not from the hospital; they're from an outsourced third-party company. This means the cleaning staff aren't permanent workers, and new faces can appear anytime. How did you discover me?"
"Shoes." Luo Zheng said coldly, not hiding anything.
"Shoes?" The other party looked at Luo Zheng with surprise, seeing that Luo Zheng was not bluffing, his face darkened, and continued, "The cleaning company has uniforms and hats but usually not unified shoes because shoe sizes can't be standardized. If the clothes are too big, they can be worn, but shoes can't be worn if they're too big. What's wrong with my shoes?"
