The Son of Neptune
In "The Son of Neptune" Percy has lost all memory but for little scraps and pieces of his past. What he does find though is that two Gorgons are chasing him, calling out to him "You have killed our sister Medusa, you must perish." Percy has no recollection of this happening, and as most people would he ran from them. The gorgons chased him for many days and nights, up until Percy ran into an old lady, named June. June asked Percy "Provide me with a favor or live safely under the sea and everybody and everything destroyed." Percy, being one to not sacrifice others for his own good, performed this favor for her. Carrying her across the river Tiber, Percy lost his immortality which he obtained from the river Styx. June, after the favor being completed, announced that she was actually Juno or Hera, in Greek Mythology. Juno instructs Percy with a prophecy of what he should do and what will happen if he does.
"I've got this." - Frank Zhang
I loved the Heroes of Olympus books, and I think that this series will be even better. Riordan writes with such fluency that captures every moment of the story line. It was really hard to put this book down, there was just so many action packed chapters that I would finish one, and then another would start.
I would recommend this book to anyone who likes fighting and some pretty good dialogue. This book is great for those who need a good read, but you still need to read the first one.