A gripping psychological thriller that will have you hooked

This book began with a catchy beginning and got me hooked. But after a while I got bored with the going back and forth into the main characters pasts. I am a reader that likes to move forward in a story and see developments taking place. Not a lot happened although there were a few twists during the story that I didn't expect. But the big reveal was one I had thought about at the beginning because there were a few subtle clues in the writing. There was a lot of action near the end but the conclusion was surprisingly flat, in my opinion.

The book had a good premise but had trouble following through.