I'm midway through book 6, so no spoilers beyond that please.
I've been trying to game out, in my mind, how this series can end. For the most part, each book has been one floor. The first book was the first two floors. Another book covers two floors in a different way. The dungeon is said to have 18 floors, and Dinniman has said the series will end with the 10th book.
So, setting aside my predictions (because predictions reference spoilers, even without declaring them), a couple things have become apparent to me the more I think about them.
Firstly, Carl is said to be a Coast Guard veteran, and a lot of military guys identify themselves and each other by rank and last name. We don't know either, which is super weird given his background. They've never been mentioned once.
Second, nobody seems to have a smartphone or watch or anything like that. I just came across a scene where Carl guesses at the date. Smart watches might only last hours (or days?), but some regular watches have 10 year batteries. The date should be a known quantity. Also, someone with a phone could just switch it off, and only turn it on when they need something, even if it's just to look at their photos.
My theory on these anachronisms is that these details would just get in the way of keeping the story moving forward at the pace it is, since it never really slows down. But, it still makes me curious why they aren't mentioned.
I'm probably missing some. Anyone else catch anything that seems to be missing?