To secure his second letter, Percy and his friends Annabeth and Grover agree to a new quest – pet-sitting for the goddess Hecate while she’s away over Halloween. They just need to follow her simple rules:

 

1. Look after the pets like their lives depend on it (because they do)

2. Don’t touch anything – especially Hecate’s magic potions!

3. See points 1 and 2

 

But when Grover’s curiosity gets the better of him, the trio find themselves with a giant goat, a destroyed house, and Hecate’s (terrifying and potentially deadly) pets on the loose in New York City.

 

Now the trio have twenty-four hours to find the pets and restore the mansion to order – or face the full fury of Hecate and her horrifying three-heads.