Frances Mace was enjoying a cruise with her family. She was making new friends, and engaging in a little summer romance. That is, until the Persephone, the cruise ship she was on, was attacked. Soon she was adrift at sea, and had to watch her friend Libby die right before their rescue. And when she was rescued she had to face the reality that her summer fling Grey and his his politician father were lying about the attack on the ship, saying that a wave took out the Persephone. And Fraces is the only other survivor. So, she does what any girl in her situation would do. She takes on the identity of her dead friend (with Libby's father's blessing of course) and begins to plot revenge. Until this book came out I was under the impression it was a historical. That is not a thing. It is contemporary. 
 This had the potential to be the Girl on the Train of the YA set for this year. It was billed to be a thriller featuring a complex female narrator. Frances tells us she's out for revenge. The end. But her words and her actions don't mesh up. Because even as she says this, we spend a lot of time with her being conflicted about Grey. Even as she talks about revenge, she's wanting Grey to recognize her as Frances, and practically fishing for compliments every time he mentions Frances. And the mystery and suspense of the attack itself gets lost in this central focus. I lose the sense of urgency and danger. And all of her revenge efforts feel somewhat tame. 
 All of the plotting feels somewhat convenient. We don't get to go on the discovery work with Frances most of the time. Instead, we are thrown back together after she has been inhabiting Libby's life for a couple of years. She comes back with a plan, and we are simply along to watch her implement. I think there could have been ways to keep the suspense of the unknown that his narrative strategy allows, while also letting us closer to Frances. I am fine with her being cold and distant but most of the time she felt confused. And she messed up some basic Libby traits that her confident inner dialogue should not have allowed. 
 The resolution of the mystery itself felt somewhat haphazard. The pieces went together, and they'd been set up. But, it wasn't particularly satisfying. We had some stereotypical flat bad guys wanting some stereotypical bad guy things. And it wasn't unbelievable. It just wasn't an ending that put it on par with other successful female-led thrillers floating around right now.