Nan Yu asked him how he could find the witness, and as Nan Zhan took off his gloves and walked back, he spoke while walking: "During the time the crime occurred, who would still be active on this mountain?"
"At that time, only the dim streetlights were on, nobody would go up the mountain for fun. The ones who could have passed by the scene would be..." A light bulb went off in Nan Yu's head, "the residents who regularly exercise here?"
Nan Zhan raised the corner of his lips at him: "You're getting better. And then?"
After pondering, Nan Yu said: "There won't be too many people who come here regularly for exercise, so, by observing for a week and noting down every person who comes here to run and work out, and then taking them in for questioning, we will surely find the witness from back then. Am I right, bro?"
In the face of Nan Yu's enthusiastic approach, Nan Zhan nodded: "There is someone who can help you with this, she's best at it."
