I'm not much of a mystery reader so I don't know how closely this aligns with the genre. An Instance of the Fingerpost by Iain Pears or Night Film by Marisha Pessl are the closest to mysteries I've read in the past half-decade or so, and I'm not even sure if they're mysteries. I'm reading The Goldfinch by Donna Tartt right now, and that feels like a mystery to me, too. But none of these feels like genre fiction, and neither does In the Woods (although In the Woods is closer than any of the others). 
 Although this novel dragged at times, overall the story and the way the murder investigation proceeded alongside the narrator's experiences drew me along. I'm a sucker for an unreliable narrator, and I wish French had played that up a little more without saying it as directly as she does. My biggest complaint is that there's a sort of flatness to the characters, almost like French picked out some psychological types and then applied personal characteristics to them. They didn't seem like real people all of the time. 
 I do plan to read the next book in the series, and I'm happy to see that it's about Cassie. I like her better than I like Rob, even if she's a little too wise to be completely believable.