The Third Posiden Child

After the war of Giea all Seven Half-Bloods return home and finally expect to get a break especially the great Percy Jackson. But that's easier said then done, especially when a young 16-year old girl named Demi comes to camp and turns Percy's world up side down but not as mush when he finds out his father Posiden weapon "The Trident" has been stolen! Know it was up to Percy to find and return the Trident before it's to late.