Not nearly as good as the PJO series.I found it hard to differentiate between the two narrators when I'm reading. I always has to go back and check to see who was speaking. Carter or Sadie.I also had issues with the number of events that happened in this book. There were many small and forgetful incidents that occured. When I finished, I found it hard to trace back all the things that had happended. Definately too busy. But I enjoyed learning about the different gods but there were A LOT of things that Riordan could have expained better. I'm still unsure of what exactly Duat is. The House of Life is also not well explained considering its importance to this series.So there are the reasons for the 3 stars.