One of the reasons why The Vampire Diaries remained such a popular TV series throughout its run was the way that it constantly kept the audience guessing. It managed to deliver on memorable plot twists more often than most shows, with seemingly at least one coming in every episode.
With so many plot twists to choose from, it can be difficult to pinpoint which ones were actually the most shocking. They may not have been the most pivotal to the overall storyline or the twists that changed the series completely but they are the ones that seemed to come from out of nowhere.
Tyler Becomes A Hybrid
During season 2 of The Vampire Diaries, Tyler Lockwood became more of a focal point as he dealt with turning into a werewolf. His relationship with Caroline was blossoming and entering season 3, it looked like Tyler would play an even bigger role as an ally to the heroes.
So, it came as a total shock when everything changed for him. In "The Reckoning," Klaus realized Elena's blood was key to making successful hybrids. So, he fed Tyler her blood and killed him, turning him into a hybrid. Tyler's entire character arc altered due to this, first seeing what Klaus did as a gift and then becoming his enemy.
Damon Turns Vicki
Vicki Donovan was a tragic character who spent the early installments of the show getting high and going between Tyler and Jeremy. She felt like someone who would be a notable supporting part of the series but never go any deeper into the lore of mythical creatures.
In just the sixth episode, "Lost Girls," Damon brought Vicki home, fed her his blood, and eventually snapped her neck. It was one of the worst things he ever did. Vicki was an unstable vampire and her actions led to her having to be killed soon after, which was a true stunner.
Stefan Is Silas' Doppelgänger
The Vampire Diaries dealt with the concept of doppelgängers almost from day one. Elena was Katherine's and due to that, she was a supernatural being herself. However, it was next to impossible to consider that Stefan Salvatore was also a doppelgänger.
The majority of season 4 focused on Silas, a warlock who was actually the most powerful immortal being in history. Nobody could've expected that the final scene of season 4 saw Silas come face to face with Stefan and call him his "shadow self," as Stefan was his doppelgänger.
Katherine Takes The Cure
The most consistent trait of Katherine Pierce was her effort to stay alive. The woman was a survivor at every turn, even hanging herself and becoming a vampire purely to avoid being sacrificed for Klaus to break his curse. That continued into her time as a vampire.
Katherine always put herself first, leaving others behind to die if it meant she'd live. Fans waited for her to fight with Elena on a relatively level playing field but when it happened, it was truly surprising to see Elena force feed her the cure, turning Katherine back into a human.
The Sire Line
As soon as Klaus, Elijah, and the rest of the Originals were introduced, the heroes were focused on killing them. The problem was that the Originals were so powerful that killing them or even hurting them seemed next to impossible. Another wrench was thrown into their plans during season 3.
Just when it looked like they knew how to kill Originals, it was revealed that killing one would wipe out their sire line as all vampires come from at least one of the Originals' line. For example, Trevor was part of Klaus's line and he turned Katherine, who turned the Salvatores, which led to Elena being turned. Killing Klaus would eliminate them all.
Enzo's Death
It sounds cliché to consider someone's death on a show like The Vampire Diaries a plot twist. These characters died quite often and usually were known to come back to life. Plus, there was typically a storyline building up to some of these moments. It was rare that a death came from out of nowhere.
However, that happened as the series was coming to its conclusion. In "You Made a Choice to Be Good," just as Enzo and Bonnie looked to be on the verge of true happiness, a possessed Stefan appeared behind Enzo and ripped his heart out, killing a fan favorite vampire in the most shocking fashion.
Sun & Moon Curse Is Fake
After Klaus was introduced, most of season 2 centered on the prospect of him breaking the sun and the moon curse. It was believed that this curse forced vampires to avoid daylight and werewolves to turn on the full moon. The show mentioned it in nearly every episode.
So, it came as a surprise when Elijah revealed to Elena that the curse actually didn't exist. It was a myth made up as the actual curse Klaus wanted to break was his own, which kept his werewolf side dormant. Breaking it allowed him to become a hybrid and the most powerful creature on the planet.
Hayley Is Pregnant
Hayley Marshall seemed like she would just be a relatively minor recurring character. At most, a lot of fans thought she would appeal to Tyler's werewolf side and be a threat to his romance with Caroline. Having her hook up with Klaus was a surprise on its own.
The true shocker came a few episodes later when Elijah discovered that Hayley was pregnant with Klaus' child. The whole thing wasn't supposed to be possible and became the entire setup for The Originals, at least in season one. This made Hayley a pivotal character and their baby Hope was something of a miracle.
Jenna Gets Turned
Jenna Sommers was a fun parental figure for Elena and Jeremy throughout the first two seasons. It wasn't until near the end of season 2 that she even found out the truth about vampires and other supernatural beings. That's why nobody believed things would get much worse for her so soon after.
The audience knew that Klaus needed a vampire for his sacrifice. When he didn't use Katherine, Caroline was freed, and Damon was bitten by a wolf, it was hard to see who he'd pick. Still, nobody could've predicted he would turn Jenna into a vampire and use her as his sacrifice.
Caroline Becomes A Vampire
It was noted earlier that not all of these twists marked huge changes for the series. However, that's not the case here as this totally altered the course of the show. During season 1, Caroline Forbes was just the self-centered, materialistic, and often annoying friend to Elena and Bonnie.
The season 2 premiere then ended with Katherine suffocating her with a pillow, shockingly killing her. Caroline had been fed Damon's blood earlier in the day, so she woke up as a vampire. It was a change that no fan saw coming and one that turned Caroline into a fantastic character.