"While You Were Sleeping" is a drama directed by Oh Chung-hwan, written by Park Hye-ryun, starring Lee Jong-suk and Bae Suzy. It premiered on South Korea's SBS TV station on September 27, 2017. "While You Were Sleeping" tells the story of a woman who predicts unfortunate future events based on her dreams and a prosecutor who fights alone to prevent the nightmare from becoming a reality.

Lee Jong Suk plays the prosecutor Jung Jae Chan. The behavior is a bit childish. The most obvious thing is that he loves taking selfies. But there is a reason for loving selfies, which will be explained later in the plot. In addition to being naive, there is no great sense of mission. When handling a domestic violence case, it only took 5 minutes to hastily close the case without any intention of digging into the truth behind it. Of course, each character will go through a growth process. As the heroine intervenes in his life, his sense of justice and mission will gradually be awakened.

The screenwriter is Park Hye-ryun. The hit dramas "I Hear Your Voice", "Pinocchio" and "Drem High" were all produced by her. "While You Were Sleeping" is the third time Lee Jong Suk has collaborated with her. In her works, the protagonists all have certain special powers. The male protagonist in "I Hear Your Voice" can read minds, and the female protagonist in "Pinocchio" suffers from Pinocchio syndrome and hiccups whenever she lies. This one is no exception. Nam Hong Joo, played by Suzy, is an unemployed vagrant (the preview of episode 9 revealed that she was once a TV reporter), an upright middle-aged girl who can predict the future through dreams.