Nina Dobrev, who portrays the fan favorite Elena Gilbert in 'The Vampire Diaries,' will quit the hit supernatural drama television series after the fourth season finale titled 'I'm Thinking Of You All The While.' The episode will be broadcast on Thursday, May 14, on The CW.

While Elena's exit from the series is certain, the show creators are yet to reveal how she will exit the show. Meanwhile, fans of 'The Vampire Diaries' have furnished a number of theories ranging from Elena dying to Dobrev's character waking up from coma and forgetting everything about her previous life as a vampire.

According to Latin Post, the official promo for 'I'm Thinking Of You All The While' shows Elena lying in a hospital, while another shot suggests that Elena is in a coffin. All these have sparked off speculations that she'll die in the final episode of Season 4. However, there are other rumors hinting that Elena will be in a coma for nearly 60 years!

The report says that one fan wrote, "I just read that Elena is going to be in a coma for 60 years. It sounds like a great idea, and it makes a lot more sense than her just leaving everyone behind."

While fans will know what happens to Elena after 'The Vampire Diaries' Season 4 finale ends on Thursday, but recently executive producer Julie Plec noted that there might also be a flash forward.

Talking to Entertainment Weekly, Plec said, "The season ends with a flash forward," adding, "The show's not cut yet, so by the time I'm done with it, it might not, but currently it does."

According to the official synopsis of 'The Vampire Diaries' Season 4 finale episode, Bonnie will take matters into her own hands when she discovers herself at the receiving end of a bitter plan. It also says that Stefan and Caroline will decide about their relationship, and meet Liv, which will encourage Tyler to take a drastic decision that will change his life forever.

The synopsis reads, "Meanwhile, Lily's reckless actions cause Stefan to realize the lengths to which his mother will go to reunite with her "family". Finally, after a devastating chain of events, Damon is forced to make the most difficult decision of his life."

Fans will also see Elena's brother returning to Mystic Falls in the finale.