Very much a "what the hell?!" book, although not in a bad way. Atmospheric, oppressive, weird as anything and without a sympathetic character in sight, VanderMeer's short and creepy novel works precisely because of how all those elements fit together. It's a book that requires you to enjoy a puzzle even if you're not sure about its solvability and a book that, rather like China Mieville when he's not being overly long, asks you to embrace the strangeness and see where it takes you.
I have the next two books on hold at the library, so I'll let you know when I find out.