AUNT HARRIET'S UNDERGROUND RAILROAD IN THE SKY

Cassie Lightfoot, whose soaring journey in Tar Beach (1991) garnered a Caldecott Honor, flies again. She and little brother Be Be are ``among the stars, way way up,'' when they happen on a train emblazoned with ``Go free north or die''; the conductor is Harriet Tubman. To Cassie's distress, Be Be boards the train; but ``Aunt Harriet'' joins Cassie in the air, telling her about slavery (as represented in five powerful paintings) and what it would be like to make the perilous journey to freedom. Cassie is shown following the trail, taking refuge in an attic, looking for such signals as ``a star quilt flung on the roof,'' hiding in a coffin, and finally flying over Niagara Falls to Canada. The transitions here—especially those involving the literally depicted locomotive, which symbolizes more realistic journeys like Cassie's; and the separation between Cassie and Be Be, who are touchingly reunited at the end (the train has vanished without comment)—are somewhat confusing; the vividly phrased narrative holds attention, however, while Ringgold's robust, authoritative paintings are splendid. Among many memorable images are dark, crowded rows of barely suggested faces on a slave ship; ghost-white slave-catchers lurking as Cassie makes her escape; and Cassie triumphant above thundering falls, painted in broad, free strokes. . A unique and creative vision. Historical note; brief bibliography. (Picture book. 4+)