Tsutomu Nihei, master of the mysterious architectural monolith, brings his genius to bear on the fantasy genre for the first time. Having established himself with hit series like Blame! and Knights of Sidonia, he has now created a gritty, dark fantasy world and populated it with evil sorcerors and unique undead horrors.
The ingenuous farmboy Yuva must accompany a contingent of knights through the increasingly dangerous floors of massive tower on the way to rescue the princess, Nihei bringing his unique sensibility to bear on a crumbling world of malformed creatures, wounded soldiers, and labyrinthine darkness.

The Reformed Unit Seven of the Royal Guard—composed of Yuva and friends, with the addition of Iscale and his Anti-Nausea Alliance—are facing down not one but two fearsome tower guardians. Meanwhile, at the fortress below the tower, big changes are on the way for both the Excavators Guild and the Parliamentary Defenders…and even farther away, news of the Dragon Tower and the old king's death has reached the Eastern Lands across the sea…!