Death Can Wait, I Need to Graduate: After her shocking death in last week's episode, Bonnie the ghost is on a mission in the finale, to bring the veil back up...even if it means crossing over to the other side for good. "It's a bittersweet journey for her and she has to prepare to make that sacrifice knowing that it will be the thing that separates her from her friends forever," Plec says. "But in the midst of it all there's graduation. [Laughs.] And there's her friends together and she's going to make damn sure she doesn't miss that!"

Slow Burn: In a departure from the first three seasons, TVD played it slow and steady with season four's big bad, Silas, a conscious choice made by Plec and the writers.

"We definitely knew that we wanted to slow-play the beginning of the mythology this season and rather than instantly set up a bad guy and an agenda, it would be a mystery not only to our characters, but to the audience as well," she explains. "Being able to unfold the mystery of Silas over the course of a season had its pitfalls and also its benefits, and I think ultimately, when the audience sees how it ends in this episode, they may start to understand the choices we made and why we made them."

The Vampire Diaries season four finale airs tomorrow night at 8 p.m. on the CW. Check back with us tomorrow for more exclusive scoop from Plec on "Graduation"!