The story begins with Serge, a young man living in El Nido, a tropical archipelago home to ancient natives, mainland colonists, and mysterious beings known as Demi-humans. One fateful day, Serge slips into an alternate dimension, one in which he drowned on the beach ten years earlier and never survived to the present. In this strange parallel world he crosses paths with a bold and quick-witted thief called Kid. Joining forces with her, Serge takes part in a daring heist at Viper Manor to steal a coveted artifact known as the Frozen Flame. In the process, he uncovers a startling truth: a decade ago, the very fabric of the universe split into two divergent dimensions, one in which he lived and one in which he died, and his fate is bound to both.