As with earlier volumes in the series, I really like it, but I can imagine all the details on thinking up experiments to verify how the dungeons work and their potential influence on every day life might be a bit boring for some. The characters remain a bit undeveloped, but I am not reading the series for those anyway. I do find some of the actions and events a bit questionable. Are Japanese really that naive when a group of European mercenaries clearly has no compulsion to do some serious harm to them? Would somebody really be so stupid as to mimic the voice of a famous person instead of picking just a a voice from somebody not associated with the dungeon at all like say their former boss who they dislike anyway? Mind you, the trust of the villains in their voice recognition software is a bit too strong as well (especially since it was a recording from a smartphone), but at least that I can throw on the tech being a bit more developed in the book's setting as opposed to real life. Anyway, a good read despite some minor questionable happenings.