At the end of Rick Riordan's The Heroes of Olympus, Book 3: The Mark of Athena, Percy and Annabeth confronted their fate and dropped down to Tartarus to shut the Doors of Death from the inside, but what if they accidentally crossed the line?
The Mane 6 travel to the world of Percy Jackson and find out that they are demigods, daughters of greek gods. They train with the other demigods and they are claimed by their parents .