Julia and Marcus live in a city that seems ordinary—until shadows begin to move on their own, and mysterious envelopes hint at a hidden danger. Drawn into a world between light and darkness, they uncover the existence of the Remnant: ancient entities that feed on fear and perception. Guided by cryptic warnings and an enigmatic historian, the pair must confront the darkness, protect themselves with ancient rituals, and learn to survive. But as the day fades, so does safety, and the city’s shadows are always watching.