Returning to Half-Blood Hill

After the disaster at Goode High School, Annabeth and Percy took a taxi back to Camp Half-Blood. Dionysus was out so a man named Quinton was training swordsman and he had an enormous hellhound as a pet. At Camp Half-Blood was Grover with a lot of old satyrs who were talking about the search of Pan and they will give Grover one week to find him. Tyson told Percy that there are a lot of monsters and titans trying to attack Poseidon under the sea, but the god wants them out of danger in the camp. On the other side, ina dream, Percy saw that Nico di Angelo is alive, he wants his sister back, and he may have a revenge against someone in order to complete his objective.

"I stared at him. Tyson had faced down fire-breathing bulls and sea monsters and cannibal giants. "Why would you be scared of Grover?" "Hooves and horns," Tyson muttered nervously. "And goat fur makes my nose itchy."" Tyson explained to Percy that he has been under the sea and fight a lot of monsters and titans that want to kill Poseidon; Percy does not understand how can the cyclops be afraid from Grover who is a friendly satyr.
"Annabeth had always admired Luke, the former head counselor for Hermes who had betrayed us and joined the evil Titan Lord Kronos." Hermes was in the side of the gods, but now he had betrayed them and will help the Titan Kronos to kill them and have the control of Mount Olympus again after a lot of time.

Percy is having problems again and also, strange things are happening in Camp Half-Blood. Finding a half-blood such as Quinton with a big hellhound as a pet is not something normal nor finding an old half-blood. The gods, also are having problems and changes because Hermes changed to the evil side and Poseidon is trying to avoid monsters that want to kill him. Percy was told in dreams that Nico di Angelo was going to get back his sister through a revenge. If Nico is going to take revenge, who will be the affected?