I got this from the library and read it in one day. An excellent example of the YA fantasy adventure genre and final book in the series. Percy and his friends defend Olympus from Kronos while the gods are off fighting one of the most powerful titans to be roused in the war. More monsters, betrayal by friends, hard decisions with mortal consequences, and great action. All the threads are gathered, prophecies fulfilled, and questions answered. Percy finally grows into his leader role and winds up the series as a true hero. Highly recommended.