The greatest threats are the ones unseen.... For what seems like the first time, Elena and her friends are happy. Elena and Stefan have built a home for themselves in Dalcrest, and all of Elena's friends are as in love as she and Stefan are. Even Damon is enjoying visiting his favorite old haunts in Europe, and is more surprised than anyone that he's traveling with Katherine. But lately, Elena's Guardian senses are on edge, and she can't ignore the...