The son of a North Korean spy decides to follow in his father’s footsteps to protect his little sister. After his father’s botched espionage mission, North Korean Myung-hoon and his young sister Hye-in are sent to a labor prison camp. In order to save his sister’s life, Myung-hoon volunteers to become a spy and infiltrates the South as a teenage defector. While attending high school in the South, he meets another girl named Hye-in, and rescues her when she comes under attack. South Korean Intelligence soon discover Myung-hoon’s activities and begin tracking him, all the while his own government sends a vicious assassin to eliminate him.

Byung-du is a 29-year-old career criminal, working for the middle-rank enforcer Sang-chul. Burdened with a terminally ill mother and taking care of younger siblings, Byung-du is feeling financial pressure as a substitute patriarch. When the big boss President Hwang is cornered by a corrupt prosecutor, Byung-du volunteers for a whack job and wins the big man’s trust.