I'm pretty sure this was supposed to be a thriller, but the only way I was able to finish it was by treating it as a comedy. This was truly so bad I found myself laughing at loud. If you can make it to the end, rest assured that the twist will send you right back to the beginning of the book -- where, suddenly, the introductory chapters make absolutely zero sense. I'm genuinely amazed this was published. If you just can't finish it, spoilers here :

The clues lead you to believe the the evil EJ on Adrienne's tapes is Tricia's husband, but that's just a red herring (which is a decent one, credit where credit is due) only for you to find out that Tricia is the Patricia on the tapes who killed her fiance and best friends--and she is also the murderer of Adrienne. Adrienne herself killed EJ. Then you find out that Ethan actually is a bad guy too: he killed his mom for her money. So together they murder Adrienne's innocent boyfriend Luke, buy the house, and raise their children there.