"The Originals" and "The Vampire Diaries" fans have a lot to look forward to this season!

In an interview with E! News, Julie Plec, the executive producer of both shows, dropped spoilers about a huge crossover that will take place when "TVD" star Nina Dobrev takes a trip to "The Originals" universe.

According to Plec, the crossover will appear in a flashback, however Dobrev won't be playing Elena Gilbert; instead she will play the original doppelganger Tatia, whom Klaus and Elijah were both in love with in the past. However, Tatia's life came to a tragic end when Esther Mikealson killed her in order to use her blood in spell prevented Klaus from becoming a hybrid, reports Entertainment Weekly.

"There was a character's name introduced a long time ago in Season 3 in association with Klaus and Elijah and how they became vampires and a girl that they both loved a long time ago who was the original doppelganger, Tatia," said the EP.

Both Klaus and Elijah were in love with Tatia, "so it's a little bit of history repeating itself like with Stefan and Damon," Plec says. "And then Esther, their mother, killed her so that she could make Klaus not a hybrid. There's lots of secrets and scandal and romance and terrible tragedy attached to her character. We'll get to go back into the past to see how that all played out." 

The showrunner also revealed that TV fans should mark their calendars to watch the crossover in episode 5 of "The Originals" Season 2, airing Monday, Nov. 3.

"When we plan our crossovers, we like to think of the most clever way to integrate 'The Vampire Diaries' mythology into 'The Originals' mythology," Plec added.

"We don't want to be doing crossovers for the sake of, 'Look at us!' You know? But in this particular case, the character of Tatia is part of their history and is kind of a dangling chad," Plec explains. "It's something we brought up a long time ago and never paid off." 

"The Originals" premieres Monday, Oct. 6 at 8 p.m. ET on The CW.