In early September 2001, S. J. Rozan, who normally writes about the private investigators Lydia Chin and Bill Smith, had just started writing her first stand-alone novel, a book about dirty real estate dealings in Harlem. (That September, a number of established writers of mystery series were lucky enough to be working on stand-alones, books with nonseries characters whose tones can differ substantially from their series. Stand-alones gave these authors unusual latitude to change timelines, characters and locales, plus an extra year or so to puzzle out how Sept. 11 would fit into their continuing characters' worlds.)