Slang lawyer synopsis: A premeditated murder case makes Piao Chang-hao (Lee Jong Suk), a big mouth and third-rate lawyer, become a genius liar and a big mouse overnight, and is framed and imprisoned. However, he was suppressed and bullied by various forces in prison, so he became a prison tycoon, making everyone feel that he is really a "big mouse", fighting evil with evil and fighting against the dark forces. His wife, Lim Yoon A, cooperated with him to save her husband, and the couple vowed to expose the people behind the scenes.