Triage follows Tin, a cold and cynical emergency room doctor who finds himself trapped in a recurring time loop. Every time he fails to save a specific patient, a young medical student named Tol, the day resets, forcing him to relive the same tragic events. As Tin desperately tries to break the cycle, he begins to uncover the hidden complexities of Tol's life and the mysterious circumstances surrounding his death. Driven by the need to change the outcome, Tin's professional detachment begins to crumble as he develops deep feelings for Tol. The series explores themes of fate, sacrifice, and the moral weight of a doctor's duty. As the loop continues, Tin must navigate the thin line between saving a life and altering destiny, ultimately questioning whether some things are meant to happen or if love can truly defy the constraints of time.