Sadie moved to Savannah where her Pa has a job building a new harbor. Moving into an abandoned light keeper's house, Pa warns Sadie and Jimmy that the lighthouse is not a safe place to play. They can play in the yard, or they can go into town. However, they are never to go near the lighthouse or go near the edge of the bluff.

""A fall from the cliff to the rocks below will kill you, and the waves will carry your bones to Davey Jones' Locker."" Pa warns sternly.

Soon Sadie learns that the house holds more secrets, but little brother Jimmy doesn't care. He finds a new friend living in his closet.

Aunt Erin knows the secret, but Ma and Pa think it is just a joke.

During the full moon of October, a storm gathers and Pa's ship is lost in the fog. Sadie wakes to find the old Lighthouse lit.

"Who's in the lighthouse?" she wonders.