This seems like such an intriguing book! First, you are met with the gorgeous yet eerily fitting cover that draws in your attention and makes you want to know more. After reading just the first few chapters, I was already enthralled with the characters. The author did an amazing job introducing them and making you want to see what happens next. I also love that it is set in the catacombs! The stories surrounding the Paris catacombs have always been so interesting to me, and I've never seen a fiction book about them before. I'm really excited to continue reading this thriller, following the four incredible characters through an otherworldly place! This is going to be a five star read for sure!