Into the Arcanum is the 3rd volume of Muhyo & Roji's Bureau of Supernatural Investigation manga series.
- Article 15: Someone's There
- Article 16: Lurker in the Grass
- Article 17: The Ghost Writer
- Article 18: Zansetsu Hirata
- Article 19: The Night Butterfly
- Article 20: Artificer Biko
- Article 21: The Landing
- Article 22: Into the Arcanum
- Article 23: The Mad Planter
Muhyo's friend Biko has a big problem. One of Biko's magic locks has been broken, and now something's escaped from the bottom level of a top-security prison for the evilest, most dangerous ghosts. It's up to Muhyo and Roji to restore order, but what will they do when their greatest fears are realized?