McKissack invites readers to gather in the ``dark-thirty''- -the eerie half hour when dusk darkens to night—for ten shivery tales inspired by African-American folklore and history. The historical links are especially potent: in the ``The Legend of Pin Oak,'' a free mulatto and his family escape re-enslavement by leaping from a cliff; in ``We Organized''—written in free verse and based on an actual narrative—a cruel owner is forced by magic to free his slaves. An African-American lynched by the KKK, and another left by a white bus-driver to freeze to death, return to haunt their tormentors; when a dying Pullman porter hears ``The 11:59,'' he knows it's time to go. Each tale is told in a simple, lucid style, embellished by a few deftly inserted macabre details and by one of Pinkney's dramatic, swirling scratchboard illustrations. A fine collection that teaches as it entertains. (Fiction. 10-13)