In an interview with The Hollywood Reporter, Plec spoke about Elena's (Nina Dobrev) transformation into a vampire, and the impact it will have on her love triangle with Stefan (Paul Wesley) and Damon (Ian Somerhalder)
"It's a journey for her of an adolescent growing up to a really tragic adulthood. We change a lot in those years and we change what we want out of life; it's a constant evolution," Plec teased.
She went on to explain that the brothers' opposing viewpoints on what being a vampire means will only increase Elena's confusion, forcing her to choose between them once again.
"Stefan, rightfully so, is terrified she will hurt someone and that she will not be able to deal with having hurt someone so he's going to have to do everything in his power to keep her from getting herself into those situations.
"Damon, also rightfully so, is convinced that it's inevitable that vampires hurt people; it's what they do. He wants to "rip the band-aid off," as he says in the second episode, and let it bleed.
"She's, unfortunately, not getting the same advice from the two people she values most in the world. It's going to make it more difficult for her."
Plec also suggested that the characters, and in particular Damon, will take time to grieve Alaric (Matthew Davis), who died in the season three finale.
"It was our way of tipping our hat... to the Alaric character, who we wanted to make sure we got to properly mourn and say goodbye to before we moved into our new season and our new story.
"It's very important for us to have Damon have somebody that he's that connected to. The question this year is: Who will that be? Will he be able to grow stronger with his brother? Will he be able to find a new wingman, a new team bourbon replacement?
"Will that person become Elena or somebody that we wouldn't expect? He's trying to mask it but he's feeling a little lonely."
Dobrev has described the show's fourth season as "really intense".
> 'The Vampire Diaries' season four clip: Elena wakes up
> 'The Vampire Diaries' season four character portraits - gallery
Season four of The Vampire Diaries will premiere on the CW on October 11. Watch a promo for the new season below: