"Familiar" (Graywolf Press, 224 pages, $15), the new novel from J. Robert Lennon, opens with an instance of sudden and dramatic dislocation. While driving from her son Silas' grave in Wisconsin to her home in New York, Elisa Brown idly focuses on a crack in her car's windshield. Suddenly, the crack vanishes, and Elisa finds herself living in a version of her life in which many things have changed -- not the least of which is the fact that Silas never died.

Despite that, this timeline is hardly blissful. Elisa's marriage is rooted in vaguely sinister regimentation, her job is less fulfilling than the one it supplanted and her relationship to both of her sons is dominated by silence. As with his previous novel, "Castle," Lennon is exploring the aftereffects of trauma, with both books featuring protagonists in denial about certain aspects of their lives. For Elisa, it's that the son she mourned might not have been the kindest of siblings; the gulf between the version of her other son, Sam, in the world she left and the Sam she encounters for much of the book is haunting, his level of self-knowledge sadly truncated.

Lennon posits a number of explanations for Elisa's situation. Has her consciousness been transported to a parallel world? Is she undergoing a psychological collapse? Is the fact that one of her sons is a video game designer given to pronouncements such as "Stories exist to make sense of life" significant? Lennon leaves these possibilities dangling, but his concerns here are less with the causes of Elisa's displacement and more with its effects on her: the way the small joys of one world become wrenching horrors in another; the fact that a nominally healthier marriage may exact a severe emotional toll; that the blessing of a newly living child may be outweighed by the burdens he places on those around him.

Elisa's shift in reality calls to mind other novels that cover similar territory: Will Self's "Great Apes," in which an artist finds himself in a world where human society has been replaced, or Alex Shakar's "Luminarium," whose protagonist's life seems to be manipulated by his deceased game-designer brother. Unlike them, however, Lennon's novel acts as a kind of case study, exploring how Elisa deals with the changes in her life as opposed to seeking a reversal of them. It also allows him to effectively utilize ambiguity, both around the source of her dislocation and in terms of Elisa's altered familial dynamic. Lennon raises unsettling issues, and Elisa -- alternately capable at understanding the particulars of her new life and painfully frustrated by the circumstances of it -- faces the brunt of them. The questions posed by this novel shift over time from the metaphysical to the moral, and in the end, "Familiar" stands as a resonant and haunting riddle.

Tobias Carroll is managing editor of Vol.1 Brooklyn. He's online at thescowl.org and can be found on Twitter at @TobiasCarroll.