民国初年，西南地区江州局势混乱，更引起诡案频发。留洋归来的秦火乐（夏之光 饰），与侦缉队长宋河（吴希泽 饰）乱世相遇，携手共探诡秘。在女法医范小梵（王之一 饰）帮助下，三人以满腔赤诚与智慧，拨开笼罩在百姓头上的血色迷雾，守护人间正义。

Follow Miguel and his accomplice Lilí, who are attempting to retrieve a treasure from an underwater shipwreck of a Spanish galleon that sank during the War of Independence on the Atlantic coast of Mexico. The pair must ask for the assistance of a group of bandits to accomplish the underwater heist but they later find out they are not the only ones after the forgotten treasure.