The companion novel, A Guardian of the Boundary, is complete.
A tomb raider who barely survived has the soul of a female ghost hidden inside him. After investigating, they discover that the ghost was a fellow countrywoman who met with disaster in northern Myanmar, and the relevant authorities immediately launch a rescue operation.
A letter from another realm suddenly appears, and its contents shock everyone: for the first time in thousands of years, a crack has appeared in the boundary between the underworld and the human world. The Thousand-Eyed Ghost King is suspected of leading a hundred ghosts in a rampage into the mortal realm.
Strange cases erupt across multiple regions, and a mysterious agency finally steps into the open, renamed the Zero One Investigation Bureau.
The guardians of the boundary join forces with people of extraordinary abilities to continue their journey.
