@All rights reserved to Rick Riordan for his characters
After defeating Gaea and Khronos, Percy is broken; why? Annabeth is dead. She dyed in the war saving Percy, and now he blame himself for her death.
But, peace is not still here, Erebus(the primordial god of Darkness) and Thalassa(the primordial goddess of sea) attacked the forests, threatening the Huntress that live there.
And lastly sorry for my grammar errors, english isn't my main language....