Eleven-year-old Nicholas Vargas's life is turned upside-down when his father remarries and moves him and his new family to Florida; but when an expedition to a nearby lake turns up a little nixie, Nick, his brother Julian, and step-sister Laurie have to figure out a way to stop a horde of rampaging giants.

Nick,Julie, Laurie, and their friends try to prevent a hydra from destroying Florida.

"The Greek and Roman demigods will have to cooperate in order to defeat the giants released by the Earth Mother, Gaea. Then they will have to sail together to the ancient land--Greece itself--to find the Doors of Death"--Provided by publisher.

Jack the Giant Slayer tells the story of an ancient war that is reignited when a young farmhand unwittingly opens a gateway between our world and a fearsome race of giants. Unleashed on the Earth, the giants strive to reclaim the land they one lost, forcing Jack into the battle of his life to stop them. Fighting for a kingdom, its people, and the love of a brave princess, he comes face to face with the unstoppable warriors he thought only existed...

Gilly and her friends must prepare for a giant invasion after Jack plants magic beans, earning him a spot in Fairy Tale Reform School and reminding Gilly how good it feels to be bad.