Remember those visions that Elena has been having with this big knot in your stomach? Well, dreams are going to become even clearer. The nail in the coffin - pun intended - is that Katherine is having exactly the same views, but it is she who recognizes the location, which leads to where Stefan might be.
Grayson Gilbert again! No, not of death, but in a flashback. People will see Pope Gilbert again when a younger Elena caught off guard while you are busy with work in his basement, which can hold some secrets.