On the night of his 19th birthday, Sung Hae-Sung dies in a sudden accident. Twelve years later, he wakes up on the rooftop of his old high school, unchanged and unaware of what has happened. The world around him has moved on—his friends are now in their thirties, his family has scattered, and his childhood love, Jung Jung-Won, is living with the quiet grief of his absence. Stranger still, Hae-Sung begins to notice odd abilities surfacing, including the power to heal and heightened senses, hinting that his return may not be entirely natural. As he searches for answers, Hae-Sung discovers something far more painful: on the night he died, he was wrongly accused of murder. The scandal left deep wounds in the lives of those closest to him, pulling them apart in the years that followed. Determined to clear his name and reconnect with the people he once cherished, he begins to unravel the truth behind his death. Hae-Sung’s return is shrouded in mystery, and as the clock ticks down, he starts to sense that his second chance at life won’t last forever.