At the end of the Chu Dynasty, the legend of the "Blood River Treasure" spread in the world. Legend has it that this treasure contains secret treasures from previous dynasties and the art of immortality, and is guarded by the "Twelve Guards of the Blood River" for generations. Twenty years ago, the Blood River Guard suddenly disappeared, and the clues to the treasure were cut off. Nowadays, a mysterious organization "Night Owl" suddenly appears in the world, specializing in assassinations and intelligence transactions. Its leader "Black Feather" is so ruthless that no one has seen his true face.
