This December marks the fiftieth anniversary of Oedipa Maas’s first appearance in print, as part of “The World (This One), the Flesh (Mrs. Oedipa Maas), and the Testament of Pierce Inverarity,” a story Thomas Pynchon published in the December 1965 issue of Esquire. Oedipa’s novel, The Crying of Lot 49, would be published in full in March 1966. Where would postmodern literature be without her? Where would critical definitions of postmodernism be? And why does this slim novel continue to exert such power over us? As a ubiquitous book turns a half-century old, these are questions worth reflecting on anew.