In this chapter, the young narrator tries to figure out what's going on with his sister. He wants to know if she's been sent abroad by the mysterious "gong ou." He also wants to find out if there's a way to hack into someone's phone. He's curious about the kinds of phones that can be hacked, and he's also curious about who's using their phones. He doesn't want to hack his sister's, because his adoptive parents have told him that they don't approve of their daughter's relationship with him. The narrator wants to take revenge on the person who made him unhappy. He decides to give his sister a "great gift" by finding out what happened to her three years ago.