Just finished Mark of Athena.... 
 Absolutely amazing! And the ending is just... whoa! Such a big cliffhanger! Why Rick Riordan, why must you leave us force us to wait almost an entire year before finding out what happens next!?!? 
 I must say, this is my favorite book in the heroes of Olympus series. 
 I definitely recommend this to... well anyone! I love it so much, and I think everyone should give this amazing book a shot! 
 slight spoiler alert but you find out by the thirdish chapter, or somewhere in the very beginning of the book, and besides you probably just figured it out already 
 The two camp groups are united, and that means... 
 PERCY AND ANNABETH. 
 oh yes. yes. yes. yes!