In the Season 4 finale, Elena stuffed the cure for vampirism down Katherine’s (Nina Dobrev) throat, decisively ending Katherine’s centuries-long supernatural run. But how does the cure work after it’s been used? Can Katherine just become a vampire again? We speculate below.

No, that’s why she’s still human

Our first instinct is to determine that, once someone takes the cure, that person is forever human i.e. they can never be a vampire again. Otherwise, why wouldn’t Katherine have turned herself back into a vampire? She didn’t want the cure in the first place. The only reason she was after it was to get Klaus off of her back. And it doesn’t seem like experiencing humanity has changed her mind. In the Season 5 promo, she shows up at the Salvatore mansion looking like a hot mess. And, according to reviews of the season premiere, she drops this line in the episode: “I’m weak, and I’m slow. Do you have any idea what it’s like to run in heels? I have blisters.” Doesn’t sound like someone who’s loving her humanity.

Yes, but she hasn’t found someone to turn her vamp

On the other hand, that doesn’t mean she can’t turn vamp again. There could be another reason Katherine hasn’t taken the plunge. She’s not exactly the most popular of former vamps. In fact, she’s made a lot of enemies in her day and, without her super-vamp strength, she doesn’t have many ways to convince others to do her bidding. Plus, the transition to vampire can be dangerous. If she doesn’t do it right, she could just stay dead. And if there’s anything that drives Katherine, it’s her will to survive.

Yes, but Silas won’t let her

We’re not sure what Silas wants with Katherine, but he seems to be keeping her close in the the Season 5 promo. Could Katherine’s doppelganger status make her valuable to the Big Bad? After all, the reasons he originally turned vampire was to prevent Klaus from using her doppelganger blood. Now that she’s human again, she might serve a greater purpose. If that’s the case, perhaps Silas is using his considerable talents (amongst them, compulsion) to prevent Katherine from turning again.

Yes, but she wants to stay human

Katherine may talk a big game, but is there a chance that when it comes down to it part of her has enjoyed being human? As previously mentioned, she did not become a vampire for the chance to live forever or the super strength; she became a vampire to avoid Klaus killing her. Now that she’s human again, has she realized that she has actually missed it? Stranger things have happened. And there’s many a vamp - Rebekah, Elena, and Stefan included - who would probably choose to turn human if given the chance.

Do you think Katherine can be turned again? Share your theories in the comments below!

Catch the Season 5 premiere of The Vampire Diaries on Thursday, October 3, 2013, at 8 p.m. ET on The CW.

Credit: Celebified Photo: Paul Wesley Moves On From Ex Torrey Devitto With His Vampire Diaries Co-star Phoebe Tonkin