Percy Jackson has saved the world multiple times - battling monsters, Titans, even death himself - so graduating high school should be a piece of cake, right? Wrong. Percy needs three college recommendation letters from the gods before his final school year comes to an end. And one thing Percy knows, the Greek gods don't do anything for free. He earned his first one by retrieving Ganymede's lost chalice. Now, to secure his second letter, Percy and his friends, Annabeth and Grover, must agree to a new challenge - pet-sitting for the goddess Hecate while she's away over Halloween week.