Riordan books run on emotion....this one is no different. Us readers are attracted to his books in the first place by the hilarious humor but with a backdrop of strong emotion. Each character has their own heartbreaking story to tell, and the past is what shapes their character. Percy would not have a significant role in the book if not for his memory loss, as the fact that he struggled forward to see Annabeth again made us want to cry. Frank would be nothing without his sad story and the witty theory Riordan came up with that if you are powerful, then your life depends on something delicate. Frank had a lot of heartbreak in his past; faced a level of sadness that the other demigods did not. He also had the power to turn into animals, which backfired on him because his life depended on a small piece of stick. If it was burned, he was dead. This lifeline is the leverage that Riordan used to develop the character and add emotion into the story. Hazel is dead. She has been given a second chance at life and the way she died makes you want to cry. The way Riordan has used these characters, developed their characters so we as readers could thoroughly enjoy the book, is completely unbelievable. When we read his books, we feel like we are the main character of the book. We can relate to this sadness, this heartbreak, and the depth in each individuals' characters is what makes this story shine. However, not just that, the breezy humor that covers up the drama and emotion is the most lovable part of the book. One will find themself laughing every five minutes as the journey continues through its fast-paced action. Action. That's another aspect of this book we love. The way they defeat the monsters, used their differences to conquer the evil is top-notch. The book never seems to lose pace and keeps us on our toes. As a reader, we want a roller coaster of emotions jam-packed into a book, and Riordan has packaged it perfectly in this novel yet again. Kudos, Mr. Riordan. Your books are our sanctuary to a key to a parallel universe of heroes who we can relate to. We love Riordan World.