What if Yi Sun-sin had not died at the Battle of Noryang? AlthoughYi Sun-sin collapses after being struck by an enemy bullet at the battle, he survives after many twists and turns, finally bringing the seven-year Imjin War to an end. However, King Seonjo feels pathological jealousy and extreme pressure toward Yi Sun-sin, who has emerged as a hero of the people after leading the war to victory. Ultimately, Seonjo colludes with key figures of the Western Faction to secretly arrest Yi Sun-sin, frame him as a traitor, and sentence him to death. The men in Yi Sun-sin’s family are executed or exiled, while all the women are taken away as government slaves, meeting a tragic fate. In the end, Yi Sun-sin is secretly executed by dismemberment within the abandoned palace, and even his body is burned, completely annihilating him. Surprisingly, however, Yi Sun-sin unexpectedly returns to his youth, about thirty years prior. From that day forward, Yi Sun-sin devised a grand plan to conquer Japan, the Jurchens, and China, while simultaneously stopping the Japanese invaders who had ravaged Joseon and massacred its people, and punishing the future King Seonjo who had annihilated him and his family. He began to systematically put the plan into action. Will Yi Sun-sin be able to succeed in the Northern Expedition following his Southern Expedition?