This essay argues that William Gibson’s novel Pattern Recognition (the first volume of his Blue Ant Trilogy) borrows from Pynchon’s The Crying of Lot 49 as regards plot, character, narration, structure, imagery, and theme, even as it transforms these elements to reflect a post-9/11 world. The essay particularly focuses, however, on the fear and anxiety experienced by the protagonists, Pynchon’s Oedipa Maas and Gibson’s Cayce Pollard, who are among the very few female sleuths to appear in postmodernist metaphysical detective stories. It argues that Pynchon and Gibson modeled their narratives on female gothic novels in which a heroine discovers evidence of a conspiracy against her but cannot determine whether it exists or whether she imagined it. The essay thus offers a new context in which to read Pynchon’s novel, in terms of both genre and gender, as well as extensive evidence of its impact on Gibson. At the same time, the essay argues, using the examples of Pynchon’s and Gibson’s novels, that the female gothic genre has been an important influence on the metaphysical detective story, especially its depiction of investigators who project their own interpretations onto insoluble mysteries.