3.5. Good but not great. I feel like since Girl on a Train, everyone is trying to capitalize on the storyline of female narrators who witness a crime but are unreliable due to drug/alcohol/rx use. The premise is getting old for me.
That said, I didn't predict the ending and I appreciate the layers the author weaved into the storyline. It was a good read but it didn't knock my socks off. Stronger than The Woman in Cabin Ten which had a lot of sloppy loopholes.
I would recommend The Child Finder or The River at Night for thrillers that follow an unpredictable narrative.