Twenty-five-year-old Ko dreams of becoming a teacher. As a child, she was saved by Chaichana, an event that made Ko want to be a good teacher like Chaichana. However, she comes to question what it is to be a good teacher. Ko becomes a teacher as she had hoped, but being a teacher is not easy when she has to face with the education system and the administration of Phatham School.
In this fantasy investigation series, investigators from two eras must hunt for the truth in old unsolved cases, communicating only through an old radio. The signal between the past and the present only opens at 23:23.