A vampire doppelganger who is burdened by a conscience? Now I've seen everything.

Vampire Diaries viewers should prepare to welcome Janina Gavankar tomorrow night, as the actress makes her debut as Tessa, a woman from Stefan's past.

We meet her in the following "Original Sin" sneak peek, which features Stefan awakening with a startle and finding out this character saved him from burning to death and also rescued him from his watery grave. For what purpose? With what goals in mind? And what sort of history does Stefan share with Tessa?

All will be revealed shortly. For now, watch the following Vampire Diaries Season 5 clip and get ready to rekindle your relationship with The Ripper:

Look for the episode to also flashback to a distant time and place, while Silas forces someone to help him search for Katherine and we learn the reason why he's actually after this new human.

Any guesses? Take them now!

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