Why should anything as inventive as fiction follow a fixed form, the “narrative arc”? Like its equivalent in nature, a wave, the arc is a beautiful shape, but so many other natural patterns form our world. . . . Two novels that I see following other patterns are Mary Robison’s Why Did Did I Ever, a helter-skelter narrative spinning around a trauma; and Jamaica Kincaid’s Mr. Potter, a slow, spiraling conjuring of an absent father.