Takeaway: The difference between friends and enemies is sometimes difficult to discern.
This is a classic penultimate book. The bad guy gains power. A new character (potential love interest) is introduced. There is some tension between the main characters. And a character seems to be sliding between the good guys and the bad guys.
Honestly, I am very impressed with this series. There are other things I probably should be reading. But I keep coming back to these. For a YA series they have keep my interest more than anything recently except the Hunger Games trilogy. They are not as dark as that trilogy, don’t have the same weighty moral issues and written at a slightly younger age. But I think I am enjoying them about as much.
In this story, Percy and the gang have to learn how to navigate the Labyrinth so that they can prevent Camp Half-Blood from being invaded by Kronos’ army. And Grover has to find the god Pan or lose his Searcher’s License. On to book five.