Lewis Dearborn is a lonely, anxious, "terminally shy" boy of eleven when his great-grandfather passes away and leaves Lewis's family with his decaying seaside mansion. Lewis is initially delighted with his new bedroom, a secluded tower in a remote part of the house. Then he discovers that it's already occupied -- by the ghosts of seven dead pirates. Worse, the ghosts expect him to help them re-take their ship, now restored and on display in a local museum, so they can make their way to Libertalia, a legendary pirate utopia. The only problem is that this motley crew hasn't left the house in almost two hundred years and is terrified of going outside. As Lewis warily sets out to assist his new roommates -- a raucous, unruly bunch who exhibit a strange delight in thrift-store fashions and a thirst for storybooks -- he begins to open himself to the possibilities of friendship, passion and joie de vivre and finds the courage to speak up.