Lately I've been reading through back issues of the fascinating Archie comics series in which, in two parallel story lines, Archie marries both Betty and Veronica. In much the same way as the Archie writers tackle the concept of parallel universes and how individual choices can shape countless unanticipated future outcomes (okay, maybe a little more sophisticated), Taylor Jenkins Reid explores the massive repercussions of a single seemingly minor decision in the life of one woman, her friends and family.

After years of bouncing around from city to city, Hannah Martin is finally returning to her hometown of Los Angeles. She's in her late 20s, on the heels of a disastrous breakup, and ready to leave New York (and her married ex-boyfriend) behind her for good. She quickly reconnects with her longtime best friend, Gabby, and Gabby's husband Mark, and wonders about the possibility of reconnecting with her high school boyfriend, Ethan, too.

"Readers will enjoy spotting clever overlaps in the parallel narratives and considering what aspects of Hannah's life, if any, seem defined by The Universe rather than by human foibles."

When, on her very first night back in Los Angeles, Gabby hosts a casual get-together for their high school friends at a local bar, Hannah has that opportunity for reconnection with Ethan, and in an instant, it feels like the last decade has never happened. Interest and attraction come flooding right back. But when it comes down to it at the end of the night, will Hannah decide to return home with Gabby, or stay out with Ethan and see where the night takes them?

At this point in the story, the narrative splits in two --- much like the universe if quantum physics are to be believed --- and the roads taken by Hannah and her friends take drastically different turns. Is Hannah destined to wind up with Ethan regardless of what choices she makes? Or is she fated never to find her soulmate? Or is the truth something more complicated, messier and more satisfying than either option?

As Reid relates Hannah's story (or, should I say, stories), she also explores how Hannah's seemingly inconsequential actions have definite repercussions for her friends, families, acquaintances and even total strangers. Readers will enjoy spotting clever overlaps in the parallel narratives and considering what aspects of Hannah's life, if any, seem defined by The Universe rather than by human foibles. One can imagine many heated book club discussions of the issues raised by Hannah's story.

If there's one disappointing aspect of Reid's otherwise very satisfying novel, it's that the final two chapters --- which take place more than three years after the main storylines --- read virtually identical, with a few key obvious details changed. It's clear that Reid is trying to say something about fate and free will, about how some things are "meant to be" and others are more open to chance and circumstance. But that still makes the last couple of chapters, despite an eloquent speech that effectively sums up the themes of the book, not quite compelling enough to want to read twice.