Riordan made the Greek myths popular with the Percy Jackson series, and here he plays with the Egyptian myths with Carter and Sadie Kade. I did enjoy the first installment, but there were a few issues...
Let's start with the good stuff: characters. Carter and Sadie are really interesting characters, and I liked the differences between their POVs. They're both funny, and their reactions to their circumstances. (Sadie's freakouts over the Lord of the Dead are ridiculous.) I also enjoyed Bast. I was interested in seeing more of the Egyptian House. I thought that Desjardins was really complicated. He's a good leader and has a sense of authority despite the fact that he is of common blood. I wasn't sure how I felt about Issa and Horus. They had limited interaction, as guests in the kids' bodies, and they spoke sporadically. However, as far as villains go, Set is a dull character. He was a red-colored, cackling doomsday-er.
The writing was good, too. It had all of the humor and sharp dialogue that his other books have. But the pacing was really slow. It took a long time for the humor to kick in. Once it was there, it was a really good. The mythology was translated really well, too. The gods, and the way they take human "hosts," was explained very clearly and in a way that made Sadie and Carter's royalty believable.
It wasn't a perfect book, but the characters are so interesting that I'm putting the sequel on my TBR list.