I didn't think Egyptian mythology worked as well in this story (and I do like Percy Jackson.) There was too much luck involved in Sadie and Carter's successes - the words "Somehow..." "I don't know how..." were used to move the story forward too often, and the mythology the premise is based on is harder to wrap your head around, which I'm sure was a challenge to write. Also, it took forever to read. Not that my opinion will do anything to affect Rick Riordan's success (and I wouldn't want it to) but I was disappointed.