The film mainly follows the famous 1597 Battle of Myeongryang during the Japanese invasion of Korea (1592-1598), where the iconic Joseon admiral Yi Sun-sin managed to destroy a total of 133 Japanese warships with only 13 ships remaining in his command. The battle, which took place in the Myeongryang Strait off the southwest coast of the Korean Peninsula, is considered one of the greatest victories of Yi.

A child abandoned in a subway coin locker is sold to a ruthless and calculating loan shark and gangster boss dubbed “Mother” (Kim Hye-soo), who runs an organ-harvesting ring in Incheon’s Chinatown. Named Il-Young (Kim Go-Eun), the baby girl grows into Mother’s loyal right-hand enforcer and is groomed to be her eventual successor. But when Il-Young’s loyalty to Mother wavers, the clash between the two unleashes a merciless tidal wave of blood-soaked retribution and strife.

A missing person case involving a female university student and the victim in a hit and run case appears to be the same person. Detectives look for a witness. A witness, Min Soo-Ah appears, but Min Soo-Ah is blind. She used to be a promising student at the police academy. With her acute senses, Min Soo-Ah is able to reveal important clues on the hit and run case. Another witness, Kwon Gi-Seob then appears. Gi-Seob, who witnessed the case with his own eyes, gives contradictory statements to Min Soo-Ah. The investigation then goes through many twists and turns, while Min Soo-Ah finds herself up against the killer.