Percy Jackson:Half Blood Heroes (Book 2:The Rogue Demigod)

Months after his 1st quest,Jonah has finally adopted life at Camp Half-Blood.However,his happiness is put at jeopardy when a camper that he had befriended dies and lots of other bad things start happening at Camp Half-Blood.
But with the magic barrier at it's best,it becomes clear one thing...
There's a traitor among them!

Jonah,Ellie,Ariana,Aaron and Nalani Dalton,daughter of Demeter,decide to take matters in their own hands to find out the rogue demigod,even if that means taking the search out of Camp ground.Meanwhile,Percy,along with Mya Rodriguez,have to find answers of their own to know what actually happened to Kronos' Sarcophagus after the 2nd Titan War.