The Blood Of Olympus
This book is the 5 book in the series The Hero of Olympus. It is about Greek half-bloods and Roman half-bloods come together to fight off an evil god. There are 4 Greek demigods who are Percy, Annabeth, Leo, and Piper and 3 Roman demigods who are Jason, Hazel, and Frank. These seven demigods set out on a possible death adventure to save the world from the goddess Gaea. If you want to find out more read the book.