Flatland:

How would a creature limited to two dimensions be able to grasp the possibility of a third? Edwin A. Abbott's droll and delightful romance of many dimensions explores this conundrum in the experiences of his protagonist, A Square, whose linear world is invaded by an emissary Sphere bringing the gospel of the third dimension. Part geometry lesson, part social satire, this classic work of science fiction brilliantly succeeds in enlarging all readers' imaginations beyond the limits of their respective dimensional prejudices. In a world where class is determined by how many sides you possessesand women are straight lines, the prospects for enlightenment are boundless, and Abbott's hypotheses about a fourth and higher dimensions seem startlingly relevant today.