When his mother goes missing, Lee Ho-yeon sets out to search for her. In the course of that journey, he discovers his parents' pasts during the democracy protests of the 1980s when student activists rose up against the repressive Chun Doo-hwan regime. Reading a book written by his mother, Ho-yeon uncovers a story of hope, love and betrayal, and struggles to understand painful secrets that have been hidden away for thirty years.