Back at Fangzheng's house, the tap on the door looks like it's about to close. Fangzheng sends a text message to his team, telling them that he's encountered the killer. He's got a plan to lure the visitors out of the library so that they can't escape. The only tap that wants to see where he'll launch his attack is the one that's on the other side of the door. It looks like Fangzheng is about to leave the library, so Fangzheng has to figure out a way to get the visitors to leave. He decides to bait the visitors, so they won't know about any of the incidents in the case file that Fangzheng hasn't mentioned. He also decides to use the camera on the wall to find out who the killer is.