Vampire Diaries Stefan (Paul Wesley) will be "stunned" by an unexpected visitor in Season 6, episode 4, of "The Vampire Diaries." Photo: CW

“Vampire Diaries” viewers better prepare for a real “throwback Thursday” next week. Episode 4 of the hit CW show’s sixth season will once again be taking viewers back in time … with the hopes that a past piece of information can help Bonnie (Kat Graham) and Damon (Ian Somerhalder) return to their friends.

Last time we left off, Bonnie and Damon made a shocking, dangerous and semi-helpful discovery in their weird alternate reality of May 10, 1994 – a mysterious man named Kai (Chris Wood). It turned out that Bonnie and Damon hadn’t been alone for the past four months because Kai had been lurking in the shadows the whole time. He attempted to kill Damon in episode 3, but he later claimed that it was simply a move to inspire Bonnie to get her magic back – which worked.

Episode 3 ended with Kai telling the pair that Bonnie’s magic is the “key” to getting out of their weird world. But the synopsis for episode 4, titled "Black Hole Sun," teases that Damon might actually hold the answer to their escape.

“When Damon and Bonnie realize that uncovering a time in Damon’s past may provide clues to finding their way home, Damon is forced to relive one of the worst days of his life,” the synopsis teases. But what could be Damon’s worst moment? It may be anything from becoming a vampire, doing something evil to Stefan (Paul Wesley) or even breaking up with Elena (Nina Dobrev).

Meanwhile, in the “real” world, Alaric will get back to taking his guardian duties seriously. He’ll have an “awkward” run-in with Jo (Jodi Lyn O’Keefe) at the hospital, which will lead him to aid Jeremy in getting his life together.

But those two won’t be the only ones trying to move on in the Season 6 episode. Stefan will stick around the area long enough to show Elena “what it’s like to start over and create a new identity.”

Unfortunately a new identity is what Matt (Zach Roerig) might need after learning about Tripp’s (Colin Ferguson) dark secret. The synopsis for episode 4 explains that the Mystic Falls human will find himself in a “disturbing situation” with the founding family member.

Finally, “Vampire Diaries” viewers can look forward to an “unexpected visitor” who will stun Stefan.

"Black Hole Sun" will air on The CW on Thursday, Oct. 23, at 8 p.m. EDT. What do you think will happen in Season 6 episode 5 of “The Vampire Diaries”? Tweet your thoughts to @AmandaTVScoop.