One By One

This was an interesting fast-paced thriller. The story quickly gets started and doesn't let up until the end. The book is narrated by Claire and a mystery anonymous person and the whole book I kept theorizing on who they were. It did surprise me at the end and took a turn from who I thought was the killer! The characters were all unlikeable, but I guess it was the point, it made everyone feel suspect. I also enjoyed the epilogue and the little zinger left at the end. 
The big thing I didn't like, but was essential to the plot point, was the cheating trope. I found it annoying, as well as the characters involved.