During the Japanese colonial period, Yu Gwan-sun, who led the March First Movement, is imprisoned. However, she does not give in and unites fellow prisoners to resist Japan. The Japanese security chief, suspicious of unrest, tricks her colleagues and uncovers Gwan-sun's role as the leader, and tortures her severely. After this, Gwan-sun pretends to obey the Japanese but secretly prepares another independence movement. This movement spreads beyond the prison and into the streets. Gwan-sun is once again subjected to merciless torture. She dies two days before her release.
