I don’t like the central framing device as a rule

because I think dissociative identity disorder is really overused and often poorly researched in media

though I’ll allow it here because the character’s background is quite faithful to the real life nature of the disease. Not his strongest novel but still entirely readable 

I really wanted to like this but I really did not. I’m a big fan of thrillers and I enjoyed the kind worth killing. however, I have never read a book that made me feel so sick. This book was  disturbing. 
the amount of misogyny, sexual violence was gross. The author stigmatizes DID and bipolar disorder.  The amount of sexual violence was beyond what was necessary and was described in great detail. The internal monologue of the killer was revolting. 

I listened to the audiobook which likely made that character’s internal thoughts about women even more disturbing. The way the killer talks about women was horrific. As a woman, the language was vile. It also made me uneasy that the person writing this was a man.  

The plot was not terrible but I felt sick from the sexual violence and the killer’s internal dialogue.

Also while the book is set in a fictional town, the author gives clues as to where it would be. He  says the town is on the south shore in Massachusetts, but the author’s descriptions of the town and the geography do not make sense. For example they go home from Logan airport but the author says they head towards Lexington to get home … on the south shore. The authors grasp on the geography of the region is sloppy, like most of the book. 

I have to say, I just didn't love this book.  Women written by men are pretty hit or miss for me and this felt like a miss.  From the beginning when Hen started following her neighbor who she suspected of murder at night, in a car, and then got out of the car to investigate further on a quiet road - very unbelievable, especially for someone who was written to be not in a manic phase, on correct medication.  Like, I just can't picture any woman doing this, there is so much risk.  A lot of the decisions she made did not feel like ones a woman who has grown up in this world would make.   

As the book went on, I felt like the author really wanted us to feel sympathy for Matthew.  Like, look at this poor guy, he's had a bad life, he's been abused, he's only killing men who treat women badly.  That plot point reminded me a lot of You, actually.  

All of the characters were pretty unlikable and undeveloped, other than Hen and Matthew.  And really I don't think they were so developed as much as we just got a ton of backstory and information about them.  

Overall I picked 2 stars because it was so easy to read and I didn't want to put it down until about the last 20 percent.  At which point I stopped for almost a week before picking it up again because it was just not so engaging anymore.  It felt like everything was going to come together a little too well and I just started feeling a little bored.  But it wasn't flat out awful.  I can see how people would like it, it just wasn't really for me and I don't know if I would try anymore by this author.  

A few more spoiler-y points below...

I feel like we should be past using multiple personalities as a shocking plot device.  I will admit, when Richard brought Melissa's keychain and left it for Matthew, I had a slight suspicion of "oh, he didn't hand him the keychain, he left it on the mantle... bc how can he hand something to himself if he is his "brother".  But I kind of let it go because it had been mentioned how much Mira hated Richard, which made it really seem like he was a real person.  This also makes you wonder, if Mira knew that Matthew had a full on second personality, why wasn't she insisting he get help for that?  

The whole Lloyd cheating sideplot felt unnecessary.  I think the author wanted us to think that the marriage was rocky and maybe both of them were a little too complacent and bored, but I think that could have been achieved in another way that still could have triggered Lloyd to go over to Matthew's house for the confrontation.  

Also, the final chapter revealing that Hen had almost been raped by Dustin and that is why she felt so obsessed with the case seemed too extra.  We had already seen that she can be manic and obsessive in the flashbacks to her college experience, so it almost makes sense that she could have been so obsessive with Dustin's murder simply because she was off her meds and the murder happened on her street.  That doesn't seem too out of character based on how she behaved for the rest of the book. 

Hen and Lloyd just moved into their new house. Once Hen meets the neighbors she sees a trophy in the house that she is sure belongs to a murder victim that happened to go to school at the school Matt teaches. 

Hen goes to the police and her husband with her suspicions they aren't listening, turns out this isn't the first time Hen has made allegations against someone. Since Hen is bipolar her husband assumes she's having a manic episode. 

Told in alternating perspectives you get the POV of both Hen and Matt as the truth unfolds.