I'm always reading something, usually multiple books at a time.
So, I liked this one--only not as much as I usually like/love Jodi Picoult's books. This is in part due to the narrative structure and in part due to what felt like a barrage of twists at/near the end--including one that felt like a cheat. Without giving away details, it has to do with a character being known by multiple names.
Regarding the narrative structure--I generally enjoy non-linear story-telling. Slaughterhouse-Five and Catch-22 are my jam. I've enjoyed the reverse chronology of Pulp Fiction, Memento, and the "backwards" episode of Seinfeld. But the reverse-chronological structure of A Spark of Light made me feel frustrated from the moment the story began to move backward. Why? Cliffhanger.
The story opens upon a women's clinic in Mississippi, where an armed gunman has created an active shooter/hostage situation that has lasted several hours. The readers are introduced to a cast of characters, quickly learning the state various characters are in (no details, to remain spoiler-free). The action reaches a crescendo, and it's not clear what the result of the action is. Annnnnnd. Readers do not get to find out what the outcome is until the epilogue. Because the narrative goes back an hour. Here's what was happening with all these characters an hour ago. And an hour before that. As a result of this structure, there is a certain amount of repetitiveness--like, "I already know this"; "I already know what this leads to."
Despite all that, though, I was drawn in. The characters are complicated and their stories are not necessarily what they seem to be at first glance. I somewhat understand Picoult's choice to use the reverse chronology, and reveal details backwards.
Picoult through the characters' stories explores the emotional, legal, and medical aspects of abortion, with depth and sensitivity.
Readers who are already inclined to enjoy Picoult's writing have a good chance of enjoying this novel. Perhaps if you go into it knowing about the early cliffhanger that isn't resolved until the epilogue, you'll relax more than I could and enjoy it more.