Elena returned to her old self on The Vampire Diaries last night, but she has a new mission:

To kill Katherine.

Will she succeed on next Thursday's "The Walking Dead?" Not if Caroline Forbes has anything to do with it, as this BFF will try to distract Elena by giving her various tasks.

Elsewhere, Stefan and Damon will learn that Silas has been feeding on hospital patients, while Bonnie will remain silent about her plan to defeat Silas and ghosts will make their way to Mystic Falls... with revenge on their minds!

Watch the official CW teaser now:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.