I loved this book! It started out a bit slow, but by the middle/end I was turning the pages. The premise circulating around 20,000 Leagues Under the Sea, which is one of my favorite books, is fascinating. For the most part, it was believable enough for me to get hooked on the story. I would have liked a bit more closure at the end, but that’s my only significant complaint. Ana is a relatable and lovable character, and I did get invested. Contains the trademark Riordan humor. Read this book if you like Rick Riordan and/or are interested in science and sea exploration of the unknown.