John Venton's drunken fall from a cliff leaves his family with an embarrassing ghost. His twin children, Morwenna and Corwin, flee in separate directions as their mother, enraged by years of unhappy marriage, embraces merry widowhood. Only their grandfather finds solace in the crumbling house, endlessly painting their story onto a large canvas map. As the twins are drawn back to the house, they discover that their father's absence is part of the map's mysterious pull.