Li Shufen (Rainie Yang), a social worker who runs around all day handling many cases, receives a report of a child abuse case one day. While questioning the girl's mother, Lin Meihua (Gao Huijun), she suddenly receives news that her daughter, Yating, has disappeared on campus in the afternoon. Shufen, who is anxious, checks the school surveillance camera and finds that Yating has left with a little girl in red clothes and a strange figure. Who is this little girl? Where are they going? Following the clues, Shufen and the rescue team find a trace of someone who looks like Yating in an abandoned hospital in the mountains, but the person they find is the long-missing radio host Shen Yijun (Hsu Weining). Shufen, who is at a loss, has to take the mentally unstable Yijun home first, hoping to find out the whereabouts of her daughter. Unexpectedly, the person she brings home may not just be Yijun...