|“||He's your first love, I intend to be your last... however long it takes.||”|
The relationship between Niklaus Mikaelson and Caroline Forbes. Klaus and Caroline first interacted in the episode Our Town, when Tyler accidentally bit Caroline. Tyler was ordered by Klaus to bite her, so without knowing while they were kissing he accidentally nipped her neck, long after Klaus had given Tyler the command. Afterwards, Klaus went to Caroline's house and asked her mother, Liz, to invite him in so he might heal Caroline. When Klaus visited Caroline's bedroom, he showed a soft, empathetic side to his usually hostile and aggressive character; something that is rarely seen. Klaus discovers that it is actually her birthday, and Caroline assumes he's just going to leave her to die, but Klaus, showing genuine compassion states that he wouldn't do that, especially considering the fact that it is her birthday.
Then Klaus gave her a choice and told her he didn't have to heal her if she didn't want to. After Caroline confessed that she did not want to die, he healed her using his blood and wished her a happy birthday. From there on, Klaus displays a genuine affection for Caroline, and his attraction and love for her continues to grow.
Klaus wants to show her the world and believes that one day she'll let him. He intends to be her last love, no matter how long it takes.
As they both will be on different shows for now, there will be opportunity for crossovers.
They are referred to as "Klaroline " by fans. Other less popular names are Carolaus and Nikoline.
In Our Town, during Caroline's birthday, Tyler accidentally bites her long after Klaus' request for him to do so, which he had previously refused to do. Immediately after the incident, Tyler tells Klaus. Klaus arrives at the Forbes' home to help Caroline, requesting Liz's support in exchange for her inviting him in to cure her daughter. Liz lets him in and Klaus enters Caroline's room, after which she questions whether or not he'd come to kill her.
He asks her if she thinks that low of him to kill her on her birthday, to which she responds "Yes." He checks her bite and apologizes, telling her that she was simply collateral damage and that it was nothing personal.
He comments that he loves birthdays, and Caroline rebuffs his comment, rhetorically asking him if he was a billion years old or so. He tells her that she'd have to adjust her perception of time due to the fact that she is now a vampire, and to celebrate that she is no longer bound by trivial human conventions. He explains to her that with her immortality as a vampire she is free, but Caroline disagrees, stating that she is dying instead.
Klaus then tells her that he could let her die if she truly believed that her existence "had no meaning", admitting that he had thought about it himself several times. He then explains to her that the rest of the world is awaiting her, filled with great cities, art, music, and "genuine beauty", convincing her to want to stay alive. Klaus then gives her his blood. The next day, Caroline wakes up to find that the werewolf bite has healed after Klaus had given her some of his blood. She also found a box on the side table, with a piece of paper saying "From Klaus", as she opens the box it contains a bracelet that Klaus has left for her.
In Dangerous Liaisons, Klaus sends Caroline a dress and invites her to the ball which his mother had arranged. Initially she refuses to go. When she sees Rebekah inviting Matt, she changes her mind. Unsuccessfully, she tries to find a dress in her wardrobe that she likes more than the one Klaus gave her. She relents and wears both the dress and the bracelet he gave to her for her birthday. When Caroline arrives at the ball, Klaus notices her immediately. However, his greeting is rebuffed as she soon rushes to find a drink instead.
Klaus partners her during the waltz, during which she spends a lot of time staring over at Matt and Rebekah whilst giving an excuse of being unprepared as the reason she had worn his gown. Klaus counters by asking Caroline why she is wearing his bracelet as well. Before she can reply, he compliments her dancing abilities and she declares that she is Miss Mystic Falls and Klaus confirms that he knows as much.Later, Klaus approaches Caroline outside whilst she is watching a horse and they discuss their respective relationships with their late fathers. Klaus relays a story of how one of his horses was once killed as his father tried to kill him. Again, Caroline reminds him that she is a good person and likes people and people like her, unlike him. She then turns and walks away. He also shows her his collection of art, revealing that he is also an amateur artist and that her bracelet had once belonged to "a princess almost as beautiful as her." She rolls her eyes after hearing this causing Klaus to grimace slightly at her rejection of his compliment.
Caroline is then surprised to learn that the beautiful drawings before her are actually that of Klaus' own. He then offers to take her to see the beauty of the world, offering to take her to Rome, Paris, and Tokyo, which makes them smile. Caroline asks what is like to get whatever he wants at a snap of his fingers and comes to the conclusion that this is why he creates hybrids. The smile on Klaus' face falls and his voice deepens with threatening undertones telling her to stop making assumptions and to leave.Ignoring his words she continues to voice her realization that the reason he does this is because his father never loved him and so he believes that no one else would. She tells him the reason he doesn't connect with people is because he doesn't try. Caroline walks away in anger. Klaus' angered face falls in shock of her brutal honesty towards he almost follows her but stops himself. When Caroline returns home, he has left her another gift on her bed. Caroline discovers that he has drawn a portrait of her with a horse and thanked her for being so honest with him. While looking at the drawing that Klaus drew for her she has this confused and touched look on her face.
In All My Children, Damon concocted a plan to try and get Elena out of harms way by trying to find a loophole; If one were to stab an original, all four would fall (excluding Klaus). In order to do so, he needed a distraction so that Alaric could puncture Kol without Klaus knowing.
This so happened to be Caroline. As Caroline walked into The Grill, Kol made a pun toward her, calling her a "tasty little thing", leaving Klaus to act protective over her and reply, "Say another word, and I'll tear out your liver."
After Caroline rejected his advances when asked if she would like to have a drink with them, acting upset, Klaus commented "Isn't she stunning?" and took his response, "She certainly looks good walking away from you", as a challenge to continue pursuing her.
Klaus gulps his drink down, then follows Caroline as she walks outside, almost getting hit by a car. He calls out to her and she responds, "Are you serious? Take a hint." Klaus continues to charm her, and apologizes about the little "spat" they had. She replies that she just wants him to leave her alone, as he still insists for her to "take a chance, talk to me, get to know me. I dare you." He smiles, and she agrees. She asks him, "What do you want to talk about?" and he responds, "I want to talk about you. Your hopes, your dreams, everything you want in life." She responds that she cannot be seduced by him, and he cleverly remarks that that is the reason he likes her.
Klaus later feels a puncture in his heart, and goes into a rage, asking her what she did. She responds that she didn't do anything, he grabs her, asking her again. Her response is still, "I didn't do anything. Stop it." as he is hurting her. Klaus lets her go, and knows what has happened: Kol was stabbed. At the end of the episode, Klaus burns the sketches he drew of Caroline, trying to burn his feelings for her, as well.
In Heart of Darkness, it's revealed that Caroline has kept the drawing Klaus gave to her in Dangerous Liaisons. When questioned on it by a recently returned Tyler, Caroline was unable to produce an answer as to why she still has it in her possession.
In Do Not Go Gentle, Klaus asks Caroline to dance with him. At first she rejects him but says yes after Tyler agrees to it. While they danced, Klaus tells her he's leaving the next day. Caroline responses with anything but relief. He says he would invite her to go with him but he knows she's not ready yet. He tells her that he'll show her "what the world has to offer" if she shows up on his doorstep one day. Caroline just scoffs, hurting Klaus' feelings. Before Klaus leaves the dance, he promises Caroline that she'll soon be bored with her "small-town boy" and her "small-town life" and that it won't be enough for her. Caroline watches Klaus leave, with an unquestioned look on her face.
In Before Sunset, Klaus saves Caroline from Alaric and asks her to go straight home and to lock herself in while Damon, Stefan and he save Elena. Caroline nods and thanks him. He looks at her, touched, for a moment and then runs away. Caroline turns around for a second, looking at where he went, before finally running home. Caroline later was seen at Elena's house pouring drinks into shot glasses for a "victory party," as she called it in celebration of a "Klaus-free life."
In The Departed, Caroline goes to find Tyler, crying because Klaus is assumed dead and Tyler will die as well, being sired to him. Unknown to Caroline, Tyler is being possessed by Klaus so, while Caroline is crying to Tyler and saying her goodbyes, it is really Klaus. He tells her "You're strong, and you have a beautiful future ahead of you." They then kiss, which is Klaus and Caroline's first kiss, unbeknownst to Caroline. Klaus then pretends to be dying, and tells Caroline to leave. She refuses, but Klaus finally gets her to leave by starting to transform into a wolf.
In Growing Pains, when Caroline and Rebekah get kidnapped, "Tyler" comes to save Caroline but not Rebekah. After escaping Caroline is happy to see that Tyler is still alive and the two begin making out, however Klaus calls her "love" which leads Caroline to realize that it is really Klaus. She says that he's disgusting and that she has to sanitize her mouth. They find Bonnie to complete the spell and while she originally refuses to use the dark magic needed, Klaus begins ripping Tyler's heart out forcing Bonnie to do the spell.
In The Rager, Klaus visits Tyler's house and meets Hayley, a werewolf from Tyler's past. While speaking to Hayley, Klaus over hears Tyler telling Caroline to go to Rebekah's party, and assumes that something has happened between Tyler and Hayley. When Tyler walks into his dad's old office, Klaus is sitting in the chair. Klaus tells Tyler that he thinks when Tyler went to go break his sire bond he met Hayley and they shared a passionate moment. Tyler gets upset and shouts at Klaus to stop. Klaus then says angrily, "And Caroline has no idea." Tyler stares at Klaus with shock and Klaus scoffs, shaking his head and giving Tyler a look before going to answer Tyler's cell phone.
In We All Go A Little Mad Sometimes, Caroline arrives at Tyler's house with a box of Tyler's things, interrupting a heated discussion between Tyler, Hayley and Klaus. While this is a fake display to legitimize a break-up between her and Tyler, Klaus believes it. Giving Caroline, Tyler, and Hayley space, Klaus leaves with two other hybrids.
Later on, in an effort to distract Klaus while Stefan is busy freeing Elena from Klaus' possession, Caroline confronts him at the Grill. She states that she wants him to give Elena back, to which Klaus replies that Elena needs his help. He doesn't want to burden Caroline with the details because she has too much to deal with already - referring to her break-up with Tyler. She tells him that it's none of his business. In response, Klaus assures Caroline that had Tyler still been sired to him he would not have let Tyler hurt her. He then offers her a drink and she accepts, successfully keeping Klaus occupied.
Upon discovering that Elena ran from Stefan, Caroline admits to Klaus her real motives for showing up at the Grill and tells him of Elena's disappearance. Angry, Klaus gets up from his chair and proceeds to leave. She calls after him, but he threatens to kill her despite her beauty if she doesn't stop talking. In a final effort, she tells him that they have figured out how to stop the hallucinations. This garners Klaus' attention and he gives her ten seconds to tell him how.
In a later discussion between Caroline and Tyler, it is revealed that Caroline convinced Klaus to sacrifice one of his hybrids in order to stop Elena's hallucinations by agreeing to go on a date with him.
In My Brother's Keeper, Caroline is at the Lockwood mansion helping to organize the Miss Mystic Falls Pageant for the following day. While Caroline is working, Klaus arrives to inquire about the date she promised him. Caroline is initially opposed to Klaus accompanying her to the pageant as her date, but she relents after Klaus reminds her of Tyler's indiscretions with Hayley. She tells Klaus to meet her the following day at the Lockwood mansion for the event and warns him not to get her anything so much as a corsage - referring to his earlier extravagant gifts from season three.
At the pageant, Caroline is busy carrying out her duties. After chastising a server and the musicians, Klaus asks her how he's doing at helping her host. In response, Caroline reluctantly admits that he's perfect. Later, Caroline and Elena are in a heated discussion about Damon when Klaus interrupts and informs Caroline that she's making a scene. She wonders how she became the bad guy, to which Klaus suggests they get a drink and he would explain what being the bad guy is like.
As they walk along the pond, Caroline explains Elena's strange change in behavior since becoming a vampire. Klaus alludes cryptically to the sire bond as they both sit down on a bench. Caroline urges him to find a cure, and he assures her that he's working on it. As Klaus prepares to uncork the champagne, Caroline asks him if he would ever take the cure. Klaus replies by wondering aloud why he would want to cure himself of being the most powerful creature on the planet. Unsatisfied, Caroline confirms his response by asking again. He evades her question by asking her if she would take the cure. With Tyler watching from a distance, Klaus recalls that life used to be a lot easier.
He then proceeds to remove a paper from his jacket and reads from it, asking Caroline if she missed the days of being Chair of the Mystic Falls Beautification Committee and the Director of the Policeman's Yearly Raffle. As he reads, Caroline realizes that he's reading from her Miss Mystic Falls application and tries to grab the paper from him. He playfully pulls it out of her grasp and continues reading to her embarrassment. He taunts her and she becomes defensive, but ultimately ends up laughing with him.
Later, while Tyler listens into their conversation, Klaus admits to Caroline that there was one time when he thought about being human. He recalls a trek in the Andes where he encountered a hummingbird hovering in front of him. He noted the bird's heart beating rapidly and appreciated how hard the bird had to work in order to survive each day and how satisfying that must be.
In Come All Ye Faithful, Caroline acts as a distraction for Klaus yet again, so that Stefan can search for Alexander's sword that Klaus has in his possession. Klaus finds her at the Grill studying the painting he donated to the Winter Wonderland charity event. They exchange some witty banter, before Caroline compliments his "snowflake" painting, adding that there's something lonely about it. Klaus offers her champagne and initially she refuses, worried about the adults that might see. Eventually she relents, admitting that if they're going to be nice to one another she will need the drink after all. Klaus asks her if that's their thing, to which she replies that they don't have a thing.
Later on, when it seems as though Tyler and Hayley's plan to take out Klaus will be successful, Caroline and Stefan both acknowledge their guilt over betraying Klaus, and they both agree that none of them are really better than Klaus.
In A View To A Kill, Klaus is keeping an eye on Damon, who is locked in the Salvatore basement to prevent him from acting upon Kol's compulsion. After discussing Damon's failure to train Jeremy, their conversation turns to Elena. Klaus wonders how Elena is able to look over every horrible thing Damon has done in the past. He questions whether there is something pathologically wrong with Elena and if Damon has compelled or manipulated her in any way outside of the sire bond. Without any response to his probing from Damon, Klaus falters and plainly asks Damon what it is that he says to her. Klaus' change in tone and the question spark Damon's interest. Damon suspects that Klaus' questions have more to do with Klaus' relationship with Caroline than his relationship with Elena. Damon believes that Klaus is worried that Caroline will never forgive him for killing Carol Lockwood. Klaus does not deny this; instead, he accuses Damon of doing worse. Damon disagrees, claiming he has legitimate reasons for his bad actions while Klaus' does not. Klaus refutes this. Damon finishes their conversation by advising Klaus to be bad with a purpose; that you're not worthy of forgiveness otherwise.
In Into the Wild, Caroline stops by the Gilbert house surprised to find Tyler still there and Klaus still locked in the family room. Klaus greets Caroline unsurely which she responds to dismissively. Caroline then urges Tyler to come home to avoid stooping to Klaus' level. Tyler refuses, preferring to revel in Klaus' misery until he can kill him himself. Caroline compromises by suggesting Tyler gloats and multitasks by helping to clean Elena's house. They start by covering Kol's body and Klaus responds emotionally. Klaus reasons that now that his brother Kol is dead along with Tyler's mother, Carol, that they are now even. He beseeches them to call Bonnie to undo the spell. Caroline declares that she will never ever help Klaus. Klaus responds by pointing out his good deeds (saving Tyler from the painful experience of being a werewolf and feeding her his blood on her birthday to heal her from Tyler's fatal werewolf bite). This provokes a hostile reaction in Caroline, who then confronts Klaus with all the bad he's done (killing Tyler's mother, killing Elena's aunt Jenna), insinuating that his charm could not make them forget these terrible actions. Driving her point home further, Caroline refuses to discuss things further with him, claiming that he's not worth the calories she burns talking to him. This provokes Klaus, who stakes her with a lamp post. He pulls her into the family room with him and bites her, much to her surprise.
Later, Caroline is shown panicking over what Klaus as done as Tyler helps her down onto the Gilbert's living room sofa, while Klaus stares away from the unfolding situation. Tyler tries to calm Caroline down by assuring her that he'll fix things. Tyler confronts Klaus, reminding him that Caroline will die if he doesn't give her his blood. Klaus seems sarcastically receptive, biting his wrist and extending it to Tyler. He asks Tyler to beg him to save her life. Tyler scoffs at Klaus' attempt to underscore how powerless he is compared to him. Tyler relents and begs Klaus to save Caroline. Klaus states that it would be pathetic of him to help since in a previous conversation Tyler revealed that once Klaus was forcibly given the cure that he would kill him. Tyler responds by offering to be Klaus' slave again in exchange for healing Caroline. Klaus refuses him. Obviously hurt, Caroline asks Tyler to help her leave the room as she is unable to look at Klaus.
The next day, as Caroline's health worsens, Tyler brings her back downstairs and places her in the family room in front of Klaus. This is an attempt to play off of Klaus' feelings for her in hopes the sight of her dying will provoke him to save her. Klaus tells Caroline that her death is nothing personal, but as a means to achieve leverage and power over Tyler.
A few hours later, Caroline is on the couch as her health deteriorates further while Klaus stares vacantly away from her. Caroline warns him again that if he does not feed her his blood, she'll die. Klaus seems to coldly accept that reality, knowing Tyler will have learned his lesson. Caroline asks how Klaus could do something like this to Tyler, to his mom, and to her. He responds dismissively, citing boredom as a reason. Caroline does not believe him. Klaus then suggests that his actions are motivated by the fact that he's pure evil. Caroline counters this explanation by concluding that Klaus does what he does, because he's hurt. This garners Klaus' attention. She continues by suggesting that since Klaus is capable of hurting there is a part of him that is human. Surprised by her words given all that he's done, he moves closer to her and wonders how Caroline could think that.
She confesses that she's seen his humanity; that she's found herself wishing she could forget all of his horrible actions. Klaus concludes presumptuously that she can't, faltering slightly as he seems to ask her if she could forget. Caroline does not answer him directly. Instead, she points out that she knows that he is in love with her and that anyone capable of love is capable of being saved. Clearly affected by her words, Klaus ignores her claims by reducing her words to the product of a hallucination. With her death not far off, she concedes that she'll never know. At this point, her body appears to be succumbing more rapidly to Klaus' bite. Panicked, Klaus repeats her name a few times, but she is unresponsive. Conflicted, Klaus weighs his options before ultimately deciding to heal her. He props her up as he moves in behind her on the couch. He bites his wrist and offers it to her. She responds to his blood, holding his forearm and hand as she drinks, while he strokes her hair.
In Down the Rabbit Hole, Elena recapped everyone's whereabouts on the phone for Caroline. They saw signs of a struggle, so they assumed Damon has been taken and wasn't just off brooding. They asked Caroline to get Klaus' sword so they could translate Jeremy's tattoos via the photos Bonnie took and send them a map and directions. Klaus wouldn't hand the sword over, Rebekah argued. After getting off the phone, Klaus asked Caroline if she needs any help which she said no to.
Caroline and Tyler would have found the sword in Klaus' attic. The handle is a cryptex ("I've seen the Da Vinci Code," Caroline said), so they basically had to twist parts and read Aramaic, which of course Klaus knew. There's only one dose of the cure. Klaus, who'd wisely decided that he could help Caroline and Tyler read the cryptex and keep that important information to himself, shouted it out to Rebekah when Caroline phoned her to say they were emailing the translation and directions.
Later, Tyler wanted to get out of town, knowing Klaus would start with him. Caroline begged him to let her try to fix things with Klaus because she didn’t want to say goodbye to him again. Caroline tried to convince Klaus that he didn’t have to forgive Tyler, he just needed to let him live far away from Mystic Falls. Klaus resisted, and we veered off into a conversation about whether Caroline would take the cure if she had the chance. Klaus knew she wouldn’t, she’s like him: She likes being strong, ageless, fearless. That makes total sense. Caroline turned it around on Klaus: If they’re so much alike, he should show Tyler the mercy she’d show Klaus. For a moment, it appeared she’d gotten through to him. We heard the epic love theme in the background. But the only mercy Klaus would show Tyler, for Caroline’s sake, was a head start.
On Elena’s porch swing, Caroline said a tearful goodbye to Tyler. They’re immortal, he reminded her. “This isn’t goodbye, this is until we find a way,” he said. Also simultaneously heartwarming and heartbreaking was her response: She told Tyler if they couldn’t find a way, he had to promise he’d live a full, happy life without her and never think of her again. For her sake, he said it. They kissed. He slowly walked away. And Caroline sat there crying. Klaus walked out of Elena's house. He told Caroline he assumed he was free because something had happened to Bonnie. He also said he’d never hurt Caroline, and that he’d shown kindness, forgiveness, and pity -- for her.
In Because the Night, Caroline is at the Salvatores' home cleaning up after Elena's party from the night before. Clearly still upset by what happened the night before, she is seen drinking from a leftover beer cup as Klaus walks in. He notes what she is trying to do before she asks what he's doing there. Klaus sympathizes with her before joking about drinking something more sanitary. In a blatant act of defiance, Caroline takes a sip from another cup before discarding it in the trash. Klaus rebukes her attempt with sarcasm and Caroline responds by wondering why he's not out searching for Tyler, suggesting that perhaps there are still some hopes and dreams in Mystic Falls that he would like to crush before he goes.
Klaus asks if she knows where Tyler is to which Caroline responds by informing Klaus that he's not with her and has surrendered the deed to his house to Matt Donovan. Klaus steps forward and points out that it was Tyler's intent to kill him and that it's unfair of Caroline to hate him for driving him away in response. Caroline disagrees, suggesting that she does hate him before telling him to go away. Stefan interrupts at this point, informing Caroline that Stefan asked Klaus to come; that they could use his help because he thinks Silas is in Mystic Falls.
Still in the Salvatore house, Klaus helps himself to a drink as he questions Stefan's assumption that Silas is back in town. He suggests that it is Elena who is responsible for the missing hospital blood. Stefan denies Elena's involvement. Assuming that it is Silas, Klaus ponders why he should care about Silas being in Mystic Falls. Stefan explains that Silas wants to die to be reunited with his true love, but because he's supernatural if he dies he will be stuck on the supernatural other side. However, if Silas destroys the other side altogether, he can take the cure, die, and pass on, but that means the dead supernatural on the other side will be returned to this side. Caroline underscores this by pointing out that every werewolf, witch, and vampire - including the many that Klaus has killed - will return, wondering if Klaus cares yet. Klaus concedes that his interest has been piqued. He asks Stefan how they can stop Silas. From Bonnie, Stefan has learned that Silas needs three massacres to do the spell, noting that two have already been completed (i.e. the Young farm explosion, and Klaus' hybrid slaughter). He concludes that Silas is in Mystic Falls to complete the third massacre.Stefan, Klaus, and Caroline begin their search for Silas at Professor Shane's office. Stefan believes that there will be something in his office that will reveal Silas's next move. Caroline jokes about the existence of an evil villain to do list that casually lists stealing blood and performing three massacres alongside more mundane activities like picking up dry cleaning. Klaus corrects Caroline and tells her that villains usually hire minions to pick up their dry cleaning. Caroline responds by sarcastically wondering why Klaus is necessary to helping her and Stefan find Silas. Stefan reminds her that they don't know what Silas is capable of, and therefore having an immortal hybrid like Klaus on their side could be beneficial. Klaus adds that he and Stefan work well together, referring to their time in the twenties. Stefan reasons that they did at that time because his emotions were off and Klaus explains that it's why Stefan was more fun. He also notes that Damon is probably relishing in Elena's emotionless state in New York. Stefan argues that Damon knows what he's doing. Klaus questions this and warns Stefan not to underestimate the allure of darkness; that even the purest of hearts are drawn to it. Seemingly impacted by his words, Caroline interrupts the conversation by introducing a book she found that might be of use. She opens the book to a section on expression triangles for Stefan and Klaus to examine. Stefan reads from the text, which states that in some types of magic, like expression, human sacrifice can be used as a focus for power. Two additional supernatural sacrifices can compound the mystical energy that creates an expression triangle. Caroline outlines the two massacres that have already taken place, emphasizing Klaus' hybrid failure in particular. Klaus points out that it wasn't exactly a failure before urging her to reveal what the third massacre needed is. It is revealed that witches are the third sacrifice.
Still in Professor Shane's office, Klaus and Caroline are now examining a map without Stefan. Caroline notes the locations of the two massacres that have already taken place with a marker, reminding Klaus once again of how he slaughtered twelve of his hybrids. She connects both locations with a line as Klaus smirks at her. Recalling that the book dictates that the expression triangle is equilateral, she predicts the location of the third sacrifice by completing the triangle on the map. Amused, Klaus concludes that Caroline has been skipping her geometry classes. He argues that there are two possible locations for the massacre, as he completes a second triangle on the other side of the first triangle's base. In her defence, Caroline points out that Klaus didn't give her a chance to finish. They exchange lingering intrigued looks before Stefan returns to the office and informs them that he talked to Bonnie's dad and believes he's found Silas.
Later, Caroline is following Klaus in the woods as they use a map on Klaus' phone to track one of the possible sacrifice locations. Caroline demands to see Klaus' phone so that she can see where they are. Annoyed, Klaus reminds her that she did have the option of accompanying Stefan to the other potential massacre location. Caroline scoffs at this suggestion, explaining that she wouldn't leave Bonnie's life in his hands. Still frustrated, she asks Klaus if he even knows how to read a map.
Klaus informs her that he learned how to read a map from his friend, Magellan. She makes a sarcastic remark about him actually having a friend before wondering if he was drawn to his darkness too. Klaus states that he was referring to Damon and Elena when he made his earlier comment about the allure of darkness, but concludes that it struck a chord with Caroline. She denies that there is any allure to darkness. Klaus stops and turns to confront her. He asks her if she's never felt the attraction that comes when someone who is capable of doing terrible things for some reason cares only about her. Caroline acknowledges that she did once when she thought he was worth it, in obvious reference to Klaus. She continues by saying that some people can't be fixed; that people who do terrible things are terrible people. Visibly impacted by Caroline's harsh words, Klaus changes the subject back to the location of the sacrifice. Since there are no witches present, he concludes that they went to the wrong point.
They meet Stefan at the correct point where the twelve witches are attempting to cleanse Bonnie. Stefan informs them that the witches are linked and that Bonnie is going to kill them. This won't happen if the witches kill her first, Klaus points out. Caroline urges Klaus that they need to save Bonnie. He reminds her that the only way to stop the witches is to kill them, which would give Silas what he wants. With the witch ready to kill Bonnie, Caroline intercedes and drives the dagger into the witch's chest. This kills the witch along with the eleven other witches present. This puts the massacre location into darkness as Caroline ensures Bonnie is okay. Klaus and Stefan look on with shocked and defeated expressions.
Early the next morning, Caroline sits in shock as Klaus finishes burying the twelve witches who were sacrificed. Now that they are buried, Klaus concedes that it's almost like the sacrifice didn't happen, before he reminds Caroline that it did happen and now Silas has what he needs to destroy the other side. Caroline scoffs at his willingness to let Bonnie die.
Klaus argues that one sacrifice (i.e. Bonnie) is less than the twelve witches Caroline sacrificed, to which Caroline responds by emphasizing that the one witch she saved was her best friend.
Klaus replies by telling Caroline to say whatever she needs to in order to sleep better at night. The significance of what she has done begins to dawn on her in that moment and she becomes emotional. Klaus touches her shoulder reassuringly and notes that she looks like she is in need of comfort. She nods slightly and Klaus responds by telling her to find someone less terrible that she can relate to - referring to Caroline's earlier disparaging comments directed at him. Disappointed and hurt by his words, Caroline pulls away and leaves him with a regrettable look on his face.
In American Gothic, Klaus, meanwhile, was shirtless and in pain because a piece of the white oak stake was still inside his back in a spot he could not reach. Caroline arrived. She touched his face, and she said, “As much as I’d love to watch you die, you still haven’t found me that cure.” It was Silas. He can take the shape of whomever he wants you to see. Then he left. Later Klaus was sweaty and cowering on the floor when Caroline came in again. He started to think it was the real her when she quipped about how she should be running three prom committees at that moment. He told her about the white oak stake, and since he was hurt, she was the person to call. She found that hard to follow: He ran Tyler out-of-town and killed his mother. But, Klaus reminded her/us, if he dies, Caroline and everyone she knows dies. She had to help. He told her she’d need to cut the stake out of him.
Caroline was having a difficult time getting the stake out of Klaus. Caroline finally smartened up: If Klaus wants her help, he’s gonna have to let Tyler come back and promise not to kill him. Klaus could feel the splinters moving toward his heart and begged Caroline to help him, but she wouldn’t until he promised not to hurt Tyler. He wouldn’t do that because Tyler tried to kill him, but yeah, Caroline’s right, Klaus has tried to kill most of them. This turned into a conversation about trust being the foundation of friendship, and Caroline angrily yelling that she should’ve turned her back on Klaus ages ago. That was a punch to the gut, but silver lining, Klaus’ pain was gone. Silas had gotten into his head and made him think he was dying. Caroline had taken Klaus’ mind off of it enough to break the spell, apparently. Seriously, if Silas can make Klaus think he’s croaking, then what can he do to the rest of them?
Caroline was ready to call it a night after using all of Klaus’ bleach to clean up. He thanked her for her help. She poked his chest when she told him if he needs anything else not to call her because she has a prom to plan. "Friends?" he asked, all smiley and adorable. She asked if he was letting Tyler come back to town. He didn’t answer, at first. But he did then say she might have noticed that he’s not exactly scouring the earth for Tyler. She smiled a bit. So did he. So sweet.
In Pictures of You, she interrupted Klaus' fireside brooding to inform him of the "real crisis" that was Elena's prom dress theft. The tailor couldn't remember who'd picked up the gown, which meant she'd been compelled. So the vervain is out of the town's water supply. Klaus laughed at Caroline, obviously, but couldn't resist her when she smiled and begged him to go into his "creepy trophy chest of family collectibles" and find her a gown that would make her look "Princess Grace of Monaco" hot. He couldn't refuse her so he helped. He was also out of the Lockwood mansion after Tyler showed up, he asked Tyler if it worth it, and then he gave five seconds to Tyler for leaving, after Tyler goes, Klaus look at the mansion with a regrettable look, knowing that Caroline is inside.
In The Originals (Episode), Klaus was standing in a city he loved and he wanted to be with the girl he loves. He called her and said, "Caroline, I’m standing in one of my favorite places in the world surrounded by food, music, art, culture, and all I could think about is how much I want to show it to you. Maybe one day you’ll let me." Then he smiled. That reassured fans that Klaus will not forget about Caroline and would wait for her.
In She's Come Undone Silas takes the form of Klaus and shows up to Caroline in front of the Salvatore's house. Caroline is surprised to see him, and she seems glad. After that, they walk through the forest and they start talking. Caroline says that everyone said the he was gone for good, and Klaus/Silas admits that he couldn't leave before he said goodbye to her. Then Caroline tells him that he doesn't owe her anything, that he moved on and that he should just go, but she showed some sadness during that. "Klaus" declares that he never intended to move on and that the truth is he couldn't stop thinking about her, even if he tried. Caroline walks away and Klaus tries to stop her and tells her to come to New Orleans, then asks her what is she afraid of. Caroline answers: "You. I am afraid of you." This had showed that Caroline wanted to see Klaus as Silas takes form of one that any person desires to see.In Graduation (Episode), Caroline repeatedly calls Klaus for help but she still gets no reply. The witches that Caroline killed showed up to get revenge until Aja gets decapitated by a graduation cap thrown at her. Klaus saved Caroline and the others. He threatened to speed-toss more caps, and the ghosts retreated. Caroline smiled at him, happy to see him. Caroline, we learned, had sent Klaus a graduation announcement -- hoping for cash, he joked. Or a mini fridge, she admitted. He'd thought about offering her a first-class ticket to New Orleans, but then he opted for something she'd use: He was letting Tyler come back to town. "He's your first love. I intend to be your last. However long it takes," he said. He kissed her on the cheek and escorted her back home. Leaving Klaus to head off into the The Originals (TV Series) and maybe one day Caroline will join him.
Caroline mentioned Klaus in Monster's Ball.
The Originals Series
In Bloodletting, When Klaus and Tyler are about to face off in a fight, Klaus tells Tyler that he is very surprised because he is able to hurt a pregnant woman referring to Hayley only for revenge and he asks him what Caroline think about that, Klaus says that perhaps he will call her to tell what Tyler has done but after killing him, Tyler says that whatever he do to him Caroline never stop hating to him, that bothers to Klaus and react pushing to Tyler against a tree.
- Joseph Morgan ships them.
- Candice Accola has admitted there is chemistry between the two characters.
- Julie Plec said that Caroline is drawn to Klaus she may not like it but she is.
- Writers of episode reviews have also admitted they like the chemistry that is growing between Klaus and Caroline.
- Klaroline is one of the most popular couples of the show.
- Caroline thinks Klaus' jewelry gifts are expensive and Klaus' drawings are romantic.
- Before Klaus loved Caroline, he openly admitted he would kill her in episode 4x06.
- Caroline may have started to crack in episode 4x07.
- Caroline brings out Klaus’ humanity. 
- Klaus revealed to Caroline the only time he wanted to be human again in episode 4x07.
- Klaus loves Caroline, and she knows this fact.
- Klaus confirmed in episode 4x14 that like himself, Caroline doesn't want to be human again.
- If The Originals gets picked up, Caroline will possibly come into the spinoff as Joseph promised that there would be plenty of crossover opportunity, especially since both shows will film in Atlanta.
- It is not the end of Klaroline. 
- Klaroline overcame in the semi-finals to Stelena and in the final to Delena on Alloy Entertainment March Madness 2013: Favorite couples.
- The last Klaroline scene of the fourth season won: Most Rewound Moment in EW.com
- Klaroline has won many surveys on various web sites, proving its popularity.