Bone Kien: Roots

Bone Kien is a haunted castle used as a base of operations for a mercenary organization and the elite group of heroes which lead it. In the first book of the series, Bone Kien, Teven, Sir Lane, Ket and Anlette, and others defeated a demon army and staved off the revenge of a powerful sorcerer. But now, the very origins of Teven's arrival at the haunted castle are in danger, and a ghost of the castle leads Ket and Anlette to clues on the road they must travel. In the meantime, the Sage of Magic is diverted and attacked. Teven and an elite group must travel to a dangerous dimension to attempt to find and rescue him.