Elemental Darkness (Paranormal Public #8) by Maddy Edwards

Charlotte is devastated by the events of last spring, and the last thing she wants to do is return to Paranormal Public for her senior year as if nothing has happened. Unfortunately, she doesn't have a choice. As she and her friends fight to find out what happened to their friend, and hope for a bit of normalcy in a paranormal world turned upside down by darkness, Charlotte is forced to confront difficult truths: sometimes blood is stronger than loyalty, the bad guys win, and you have no choice but to lose what you hold most dear.