Under the colonial rule of Japan, 400 or so Koreans who are conscripted into slave labor on 'The Battleship Island', attempt to escape for life. 1944, during the Japanese occupation of Korea, conscripted civilians head out to the Hashima island. Nicknamed 'The Battleship Island' after its resemblance to a war vessel, some are lured by false promises of high wages. LEE, a bandmaster of a jazz bigband and his only daughter, CHOI, a thug, and Mallyeon are among the workers. But upon arrival, they found that the island turns out to be an isolated hell where the workers are forced into slave labor. As the Pacific War nears its end, PARK, a Korean independence activist assigned on a mission to rescue a Korea's spiritual leader from the island. As the U.S. launches massive counterattack on Japan, the Japanese decided to blow up the island in order to bury the truth about their awful treatment of the Korean slave labors. PARK discovers the plan, and conspires with LEE and others for mass escape of all 400 Koreans.