Synopsis: The suspense crime film "Goodbye Stranger 再見陌生人" tells that Song Yawen, a policewoman serving the people and justice, finds out a serial human trafficking gang is involved when she is investigating a child trafficking case. She finds that her childhood playmate who were once dependent on her in the welfare home is also involved. After going through various hardships, she finally brings the entire human trafficking gang to justice. When the whole incident seems to be ended perfectly, Song Yawen unexpectedly finds that things are not as simple as she imagined...