After the black fire case, Qin, deputy head of Xifeng Order at the crime scene, found Lisa and asked her to help find some information. Later, in order to thank Lisa, Jean invited Lisa to tea, during which she met Amber who was looking for the lost property with Collet.
After introducing each other, Qin invited Amber to look up information in the library, and Collet also asked to go to the library on the grounds that the library lost clues. Joan and Lisa thought about it and agreed. Looking at Collet, Lisa seems to have found something.
In the library, Lisa and Joan explain their documents to Amber. Amber found a clue in a broken file and left in a hurry. Lisa and Jean found the connection between the black fire case and the murder of Diluk's father, Klip, from the documents that Amber read before she left, so they reinterpreted the murder of Klip three years ago and found the same burning record. Joan suspects that Diluk has something to do with the black fire case and asks Rita to investigate Diluk.