"Mystery Girl" (Thomas & Mercer/New Harvest), by David Gordon The main character in David Gordon's 2010 debut thriller, "The Serialist," was a novelist hired to write a serial killer's memoirs. Now, in "Mystery Girl," he introduces a new protagonist, a failed experimental novelist named Sam Kornberg who finds work as an assistant to a private detective. Gordon writes about writers because one of the things his books are about is the nature of storytelling itself. "Does your life work like that?" Sam snaps when asked why he doesn't write "regular" stories. "Do the thoughts in your head sound like a normal book? Is there a narrator saying she did this and did that? ... Does your life have a plot?" Fortunately for readers, "Mystery Girl" does have a plot — an intricate one in which Sam's obese and not entirely sane employer assigns him to tail a mysterious young woman. What seems at first to be a simple job soon snares Sam in a murder case that takes him on a wild ride from Los Angeles to a poor village in rural Mexico and involves Satanists, free love advocates, doppelgangers and underground filmmakers. The result is a darkly comic, stylish literary thriller peppered with references to literature (Shakespeare, Proust, Kafka) and classic movies ("Vertigo," ''The Wild Bunch," ''They Live by Night"). This description of a rural church in Mexico is a good example of the author's fine prose: "Like many poor churches, it was magnificent and overwrought, festooned with glitter-and-marble icing, bedoodled with arches, niches, flying angels, singing saints, and hailing Marys. It stunned us with its space and height and cool silence, offering the people a tangible vision of heaven, a working model of the miraculous to comfort them as they died face down in the dirt and sun." The novel explores not only storytelling but also issues of faith, personal identity, friendship and the decline of civilization. Readers should be warned that the author, whose many and varied previous jobs include writing for magazines with names like Hustler and Barely Legal, has inserted a fair amount of explicit sex. While the book is not a hard read, Gordon does ask more of readers than the typical thriller requires. He's not just fooling around.