Wen Gu Wei Yu fights the mosquito demon. Hong Luan helps the demon escape by letting him take her hostage. Wen Gu Wei Yu tries to get into the immortal trap using his own blood and bone. Duan Mu gets injured and Zhan Yan goes to save her. Wen Gu Wei Yu breaks into the formation to find Duan Mu. Duan Mu is poisoned and Zhan Yan removes the poison. Duan Mu loses her human blood and starts to disappear so Zhan Yan gives her some of his blood. If Duan Mu falls in love she will endanger the world so her brother does something to her heart. The gnat babies grow up very fast on the immortal blood and end up killing a lot of people in the city. (Source: jindreame at MyDramaList)