Fukuoka Prison, 1944. Beyond the prison walls the war rages; inside a man is found brutally murdered. Watanabe, a young guard with a passion for reading, is tasked with finding the killer. The victim, Sugiyama --- also a guard --- was feared and despised throughout the prison, and investigations have barely begun when a powerful inmate confesses. But Watanabe is unconvinced; and as he interrogates both the suspect and Yun Dong-ju, a talented Korean poet, he begins to realize that the fearsome guard was not all he appeared to be.