Young-woo, an operative on the verge of leaving his organization after completing a final mission to eliminate a drug dealer, prepares to board a smuggling ship to China. However, he receives news of his mother's death, with whom he had lost contact two decades prior. Upon his return, he discovers he has a half-sister who shares his name, Young-woo. Simultaneously, his former organization learns he is still alive and begins to pursue him and his sister.
