Another YA book that I was all bored with/meh about until about halfway through - then the mystery grabbed me. It was probably a 3.5 for me, if we could give half stars. The story of a teen girl who runs into her former best friend one day on a bus - they talk briefly, and then part ways as she gets off on her stop. The next day she learns that her friend never made it to her destination, and is now missing. The story follows her as she comes to terms with some of the reasons that their friendship broke apart, learns more about who she really is, and joins Abby's friends to figure out where Abby is and what happened.