Setting: The fictional coastal city of Zhongming, famous for its ancient bell tower and frequent sea fog. The city is divided into old and new districts: the old district retains its colonial-era buildings, its narrow lanes winding like a maze; the new district is a rapidly developing business hub where skyscrapers stand alongside old houses, hiding secrets born of deep class divisions.
- Central event: During an exceptionally heavy sea fog, the worst in ten years, three connected cases occur, ultimately pointing to an unsolved mystery from a decade ago.
