So, as previously mentioned, this is not the end and there is a third and finale book. I know what your thinking, another book? When will this story finish? It keeps going on and on just stop before it gets any more crap. But yes, there is another book called Fear - Percy Jackson at Hogwarts Three.
If you are into throne of glass or just fantasy in general, I have few other stories that may interest you if you somehow like this series. Anyway, adios amigos.