The Princess in Black is exhausted after battling monsters seemingly non-stop. After confirming that the Goat Avenger will protect the goats from the monsters, the Princess's alter ego Princess Magnolia heads to the beach to relax in The Princess in Black Takes a Vacation by Shannon Hale and Dean Hale.
The Princess gets comfortable on the beach, is about to nap, and guess what? The monster alarm goes off! Poor Princess -- she can't catch a break! Instead of resting at the beach, she's battling a sea monster.
This is the fourth book about the Princess, so readers may want to check out the first three books in The Princess in Black series.