What happens to a girl and her bestfriends when they find out someone or something is watching them?

The forest has a special place in you heart and you have always loved it, though now.. the night that you turn 19 something very different and something very weird happened to you and it's something you just can't explain. You start to realize that you are being stalked as the days go by.....

I kinda suck at writing descriptions. Just read the book.