Pretty Little Liars

This series is very good. It may look very goody, goody from the cover. But let me tell you, it's probably the scariest series of books I've ever read. No lie. Its about this group of friends who has a terrible accident when one of the group, Ali, turns up missing. Now they are getting mysterious texts and e-mails from a girl called -A. But, the twist to the story is, Ali is found dead. So who is the person sending all these scary things to them, and who knows all their secrets?
I highly recommend this series for someone who get's chills from people you don't trust.