'The Vampire Diaries' season 8 spoilers, plot news: EP teases vault villain; Upcoming season a blast from past?

"The Vampire Diaries" will be returning to its roots when it comes back on air for its eighth and final season. That means elements from the maiden season of the series will manifest in the upcoming installment.

In the season 7 finale, "Gods and Monsters," Damon Salvatore (Ian Somerhalder) and Enzo St. John (Michael Malarkey) entered the armory vault after a voice that sounded much like Elena Gilbert's (Nina Dobrev) voice lured them inside. It was never known what became of the two, but according to latest spoilers for "The Vampire Diaries" season 8, the voice could have actually belonged to Sybil (Nathalie Kelley), who is touted as the upcoming season's big bad.

Speaking to TV Guide, executive producer Julie Plec hinted that the eighth season will see the series returning to its roots. That could mean Damon's character will revert to his dark version, the Damon that fans of the series both loved and hated in season 1. After all, Damon was more of a villain than a hero when he was introduced to the show, so returning to his villainous self will be like going full circle for the character.

In an exclusive interview with Entertainment Weekly (EW) at July's San Diego Comic Con, Plec and the cast members dished on the villain that was inside the vault.

"Enzo and Damon are doing some really bad things in the name of somebody who is controlling them, and so the goal is to rescue them from that situation without everybody else getting sucked into it as well. So there's a pretty high body count and a pretty gruesome method of execution for every victim," the EP told EW.

"What I like about this villain in particular is that everyone has a dark secret and there's something about this villain that just knows what it is. No matter how much you try to hide it, it will pull it out of you," said Matt Davis, who plays Alaric Saltzman in the series.

Meanwhile, as far as returning to its roots go, it looks like even the episode titles of season 8 will be a blast from the past. According to Melty, the titles will be taken from lines hashed out in season 1. Episode 1 of season 8 will be titled "Hello, Brother," from Damon's opening greeting to Stefan (Paul Wesley) when he returned to Mystic Falls.

"Today Will Be Different" is episode 2's title, which is taken from Elena's entry in her diary during her first day of school following the death of her parents. A phrase from season 1's finale episode, "You Decided That I Was Worth Saving" will be episode 3's title.

"The Vampire Diaries" season 8 will premiere on Friday, Oct. 21, on The CW.