The Vampire Diaries returns to the CW Thursday night for its 100th episode, where fans can expect more than a few plot twists to keep them glued to the screen. (Check here to see if a CW affiliate is available in your area.)

Before the show airs though, there’s a couple of things viewers need to know for the second half of the series’ fifth season. (Yes these will be spoilers if you didn’t watch all of last season).

Once vampire Stefan Salvatore (Paul Wesley) got his memories back, he went on a mission to kill a  2000-year-old witch as an act of revenge. Stefan completes his mission, but still has trouble with recalling certain memories.

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Antagonist Katherine Pierce (Nina Dobrev) vows to kill herself by jumping from a clock tower, but is convinced otherwise by Stefan, while vampire Damon Salvatore (Ian Somerhalder) becomes trapped in a cage that has his initials on the walls, a scene that left viewers wrapped up in the mystery.

During the last episode, vampire Katherine is having more and more troubles with aging. She is offered a deal to become a traveler so that she can live longer, but initially turns it down because she thinks Stefan has feelings for her. Once she finds out that he doesn’t, she goes back to accept the deal but right before she can, she collapses.

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According to TVLine, audience members can expect Katherine on her deathbed, more than a few flashbacks that longtime fans will remember and appreciate, and even more surprises than before in the 100th episode of The Vampire Diaries. As actress Kat Graham, who plays Bonnie Bennet on the show, told Zap2It, “”I definitely think the fans are going to lose their minds.”

Although what actually happens in the episode has been kept a secret, Graham has also described the episode by saying, “There are some things that happen in the 100th episode that are going to make a couple people stand on their couches and scream at their TV, ‘Yes, yes, yes!’”

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Check here to see if a CW affiliate is available in your area.

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