Murder most foul (well, we guess it wasn’t that foul) happened on the last episode of The Vampire Diaries, and the deed is stuck to Elena (Nina Dobrev) more stubbornly than the blood to Lady MacBeth's hands. Check out the second-by-second details of the promo video for Season 4, Episode 5, “The Killer,” to find out who she’s being haunted by. 

0:02 Running water
My, what a soothing shower. I hope the bathroom isn’t covered in blood, this time.

0:04 Klaus knows all
Of course, he’s had first-hand knowledge of hunter-killing consequences.

0:07 I spoke too soon
More blood in the bathroom.

0:09 Elena calls for Jeremy
Suddenly, we’re reminded of that scene from Girls with Hannah and her dad. Can’t someone else help with your shower situation, E?

0:10 Elena says her feelings out loud — to Bonnie
Bonnie is the new “vampire diary.”

0:12 Shaky cam of Professor Shane
That’s how you know he’s evil!

0:14 Shunning Stefan
Yet another bad trip for Elena. 

0:17 Dangerous Damon 
Is there a Salvatore you would like to hallucinate with, Elena?

0:18 Stefan wants to know how to bring Elena down
Let’s guess: More blood from the vein? A spell from Bonnie? Cute kitten videos?

0:20 Ooh, Elena has new-vampire hair.
Long waves. Kinda reminds us of...

0:22 Oh, just kidding.
It IS Katherine! (Or a hallucination of her.)

0:24 “Did you miss me?” 
We’ll assume she’s talking to us. Yep, we did. 

Credit: YouTube Photo: Vampire Diaries Extended Promo For Season 4, Episode 6: "We All Go a Little Mad Sometimes" — Katherine's Back!