Kang Jae-Yoon is a low level guard for the King. He investigates a case involving the serial murders of Jiphyeonjeon scholars in the Gyeongbok Palace 7 days before the issuing of the Korean written language.
Based on Lee Jeong-myeong's novel "Deep-rooted Tree". Work that highlights the serial killings during the 7 days before the announcement of the Korean script.
