See a clip from Thursday’s The Vampire Diaries episode, where Elena is in the shower – but oh no, something is wrong! Find out what…

In the last episode of The Vampire Diaries, Elena killed Connor, only to find herself suffering from terrifying hallucinations at the end of the episode.

As we learn in the first sneak peek released for “We All Go a Little Mad Sometimes,” Klaus is aware of what is happening to her, suggesting that this is a common side effect of killing a Hunter. But will Klaus know how to fix her?

The promo also shows the return of Katherine, though we don’t know yet if she’s coming back in a hallucination or for real.

The Vampire Diaries 4×06 “We All Go a Little Mad Sometimes” airs Thursday at 8/7c on The CW.

What do you think about the season so far? Find out what the Hypable staff members think on the Vampire Hype podcast, which is going through The Vampire Diaries one episode at a time! In the latest podcast episode, “April is the Key,” we discussed the fallout of the last episode of the show, “The Five,” in which we learned that Jeremy is a Hunter and that Tyler didn’t really cheat on Caroline with Hayley. A lot for us to digest, and we hope you’ll join us by adding your comments to the discussion threat.