Outliers trilogy

It all starts with a text: Please, Wylie, I need your help. Wylie hasn't heard from Cassie in over a week, not since their last fight. But that doesn't matter. Cassie's in trouble, so Wylie decides to do what she has done so many times before: save her best friend from herself. This time it's different, though. Instead of telling Wylie where she is, Cassie sends cryptic clues. And instead of having Wylie come by herself, Jasper shows up saying...