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. They just need to follow her simple rules:

Look after her pet polecat and mastiff like their lives depend on it (because they do).
Don’t touch anything – especially Hecate’s magic potions!
But when Grover’s curiosity gets the better of him, the friends find themselves with a giant goat, a destroyed mansion, and Hecate’s (terrifying and potentially deadly) pets on the loose in New York City.

Now the trio have only days to find the pets and restore the mansion to order – or face the full fury of Hecate and her horrifying three-heads. It’s going to take luck, demigod wiles, and some old and new friends to hunt down the animals and set things right again.