After his Great-Granddad dies, "terminally shy" Lewis Dearborn and his parents move into his dilapidated seaside mansion, where Lewis claims as his bedroom a cool tower overlooking the Atlantic. It isn't long before the ghosts of seven pirates, who had been living in that same room, make themselves known to Lewis. They want his help to retake their ancient ship, now restored in a museum. If he does, Lewis will get the room all to himself.