In I Know What You Did Last Summer, Emma returns home from her three month retreat. Kieran is at the door to greet her. He embraces Emma and the pair go inside her house, where Emma's friends surprise her with a welcome home party. Emma thanks Kieran for the party when the pair sit alone outside. She also thanks him for writing her letters and checking up on her. Inside of her house, she apologizes for breaking up with him before she left for her retreat but that she needed to get away from everything for awhile. He assures her that she doesn't have to apologize and that he understands why she had to leave. Emma says she really missed him and the pair begin kissing. However, as Kieran slips his hand up her shirt and touches her scar, she screams and pushes him away. He worriedly embraces her and reassures her that everything's okay. She asks if they could "just sleep" instead and he agrees. Emma wakes up in the middle of the night from a nightmare and notices Kieran isn't in bed with her. She goes down stairs to find him asleep on the couch. Later the next day at school, she confronts him about it. She apologizes for scaring him away but he claims he just didn't want to wake her up. He says he will see her later and heads to class.
In Psycho, Emma tells Kieran about her visit to Brandon James' brother, Troy's, farmhouse and how there were pictures of her there, however, the pictures were gone when she went back there with her mother. Emma asks if she's crazy but Kieran assures her that it's normal after what she's been through. He continues to tell her that ever since his dad passed away, being in his house would set him off and sometimes cause him to believe he heard his father in another room. The pair regroup with their friends when Noah expresses some worry that there are only five of them instead of six, since Jake isn't in school. Once Kieran is home, he gets a visit from Sheriff Acosta who says he's under the age of eighteen which makes him too young to be living alone. Tina, Kieran's aunt, wants him to come back to Atlanta and live with her and his cousin. Emma is deeply saddened when he breaks the news to her. That night, before he leaves, she drives to his house and asks him to take her for drive because there's something she needs to do with him and it has to be done before he leaves. He agrees. The pair end up on the dock of Wren Lake, where Emma's fight with Piper took place. She walks to the end of it, remembering everything she went through, but then turns around smiling, happy that she finally faced her fears. She runs to Kieran and kisses him. The pair end up making out in his truck. He touches her scar from where Piper stabbed her and asks if it's alright. Emma says she hates it because it's ugly, but Kieran tells her that it makes her more beautiful. The pair have sex before returning to his house. His aunt gives both of them good news. Kieran doesn't have to move to Atlanta because, thanks to Maggie speaking with Tina, she realized that she has to step up for her nephew. Kieran seems confused so Eli explains that him and his mom are moving in with him. Emma is very pleased by this and Kieran and her say their goodbyes for the night. Kieran offers to walk Emma home but she insists on going alone.
In Vacancy, Emma and Kieran are at his locker while she tells him about her breakfast with her dad, who just arrived back in town after spending many years away from the family. She tells Kieran that she wanted to cry when she saw him and he says it's natural since there is a lot of history between the two. Eli, Kieran's cousin, interrupts and says he'd punch his dad in the teeth if he showed up. Kieran says it's not a "cool" thing to say, but Emma understands and says she was so angry when he initially left that she wanted to do the same thing. Kieran says that doesn't sound like her and that he needs to cram for a Literature exam. He quickly kisses her and begins to leave but stops once Eli teases him about the public display of affection. Kieran tells Eli he has a lot to do since it's his first day, but Eli says he doesn't know where any rooms are. Emma offers to show Eli around and Kieran asks if that's okay and tells her he's a pain in the ass. Emma says it's fine and before he leaves, Kieran jokingly tells her to dump Eli off at the office where he'll take care of him.
In Happy Birthday To Me, Eli convinces Emma to throw a surprise birthday party for Kieran. In the school parking lot, Emma tells Kieran to come to her house at 7:30pm. Once Kieran enters her house she, along with the rest of his friends, jump out and yell "surprise". They all drink their shots and then she hands him his shot and tells him to drink it. After he drinks it she asks if he's surprised. He says he is, and then she continues to tell him that she was going to do something small, like he wanted, but changed her mind. He assures her that it's great, however, he doesn't seem pleased about it. He proceeds to ask her why she changed her mind and she tells him it was because Eli told her that he wanted a big party. Kieran looks unhappily at Eli and Emma notices, so she quickly leads him away to "say hi to some people". Later on, once everyone is suffering from the side effects of the ayahuasca that somebody placed in the Tequila, Kieran begins to feel fatigue. He can barely stand as he makes his way into the kitchen, clutching the wall to support himself, to yell at Eli. Emma comes in and asks what they're talking about, to which Eli replies "Kieran thinks I'm a liar". Emma says Kieran is right and asks if Eli was just trying to make her look stupid when he told her Kieran wanted some huge party. Eli assures Emma he would "never do that" as Kieran begins to collapse. Emma and Eli support him and take him to an upstairs bedroom. Emma tells Eli that she can handle things from here and he leaves the room. While Kieran is lying on the bed, Emma asks why Eli acted the way he did. Kieran tells her that he always takes things too far. He then tells her a story of when they were young and he "borrowed" a neighbors dog. He claims everyone was looking for it but couldn't find it. When somebody eventually did find the dog, it was dead. Emma is disturbed and asks Kieran if it ended up dead on accident, however, he passes out before he can answer. Sheriff Acosta comes in to question some folks who were at the party, and Emma insists on being attacked in the woods by Ghostface. Sheriff asks if anyone else saw what happened but everyone denies it, including Kieran. The next morning, the pair sit on the front porch together while unaware that Eli is listening to their conversation from inside the house. Kieran believes Emma's "attack" was just a hallucination of the ayahuasca, and admits that maybe she wasn't ready to come back to Lakewood yet. She appears hurt that he doesn't believe her, and he moves closer to her and puts an arm around her.
In Dawn of the Dead, George Washington High goes into lock-down because Jake's dead body is dropped on the stage in the auditorium. The students are confined to the library. Emma finds Jake's cellphone in her bag and doesn't know how it got there. She calls Kieran over to tell him and they both come to the conclusion that only Ghostface could have put it there. Later, when the police begin searching lockers, Kieran tells Emma and the rest of his friends that he has to get to his locker because there's something in there he doesn't want the police to find. Emma asks what's in there but Kieran tells her not to worry about it. Noah leaves to help Kieran, while Zoe and Audrey leave to distract the policewoman outside of the library. Later on, a policeman sees Kieran in his locker with a bag and demands he hand it over. The cop finds Kieran's gun and leads him away to the Sheriff for questioning. Noah calls Emma while running around the hall, trying to figure out how to get back in the library without being noticed, and tells her what Kieran brought to school. This concerns her. Eventually, the Sheriff lets Kieran go and he returns to the library with Emma, however, the police ask Emma if she has something she wants to show them. Emma looks at Kieran and realizes he told the police about Jake's cellphone. She reluctantly hands over the cellphone to the police as they lead her away for questioning. Once she gets back from talking with the Sheriff, her and Kieran argue. He explains that Acosta is a decent cop but Emma argues that he now thinks she's crazy and went straight to asking her about her personal mental issues she has been dealing with. After the lock-down is over, Kieran confronts her and apologizes for telling the police. Emma tells him that he thought that was the right thing to do, but needs to trust her to make her own decisions. Kieran assures her that he does trust her and offers to drive her home. Emma, however, insists that she needs to be alone for a little while.
In Jeepers Creepers, Emma is taunted by the killer in the morning and the only person she tells this to is Kieran in the following morning. Kieran highly recommends that Emma tell the police but she refuses, noting the sheriff might think she's insane. The same night, Emma calls Kieran to come fix her car when it breaks down. When Kieran asks where she is going, she explains that she is going for a private interview. He makes Emma promise not to go but goes back on her word and goes anyway. Kieran saw this and followed her to the fairgrounds. After escaping from the killer, he confronts Emma over lying to him. Emma insists that she needs to handle this her own way and they embrace and depart. Worried over Emma's safety, Kieran goes to sheriff Acosta and tells him about what happened.
In Let The Right One In, Emma finds out that Kieran told Acosta about keeping secrets and confronts him, feeling betrayed. Kieran tries to justify his actions, explaining that it is dangerous to keep things from the police and that he is just trying to keep her safe. Emma does not accept his apology and leaves a saddened Kieran behind. Kieran later goes to the coffee shop to talk to Emma and spots Eli and Emma together after Eli told Emma about part of the fight Kieran had with his Step-father before his death. Jealous of Eli, he leaves without making his presence known. Emma begins to distance himself from Kieran by hanging out with Eli and they even begin to kiss. Emma stops doing so however and tells Eli that she loves Kieran. She didn't have time to say anything else before the fire came and they had to leave.
In Village of the Damned, Emma, not trusting Eli anymore upon learning of his criminal record, invites Kieran back over to her house for a reunion. Admitting that she was mad and confused, she is ready to go back together with him. Upon mentioning what Eli told her, Kieran tells Emma not to hang out with Eli, claiming that "He's not right". Emma tries to tell Kieran that it's about them, not Eli but Kieran insists. Kieran later spots Eli trying to convince Emma to trust him and Kieran stops and orders him to stay away from Emma. Eli responds "It's not like I told about the worst part". Outraged, Kieran beats up Eli until Emma stops him and he goes away. Later, Kieran is abducted by the new killer, who sends Emma on a hunt for him. The killer dresses him up as a decoy, hoping that Emma will end up shooting and killing him. She nearly does so, thinking it's the killer under the mask, until the police take it off, convincing her of his innocence. Emma and Kieran bond together again when Kieran reveals that truth about the car accident and why he got mad at Eli. Kieran admits that everything good in his life, Eli tries to take and that Emma's the best thing he's ever had and he doesn't want to lose her. They then embrace tightly.
In The Orphanage, Emma and Kieran learn about Audrey bringing Piper to Lakewood and are furious at her for this. Kieran suggests Emma not go to school today but she insists. After getting into a verbal fight with Audrey, which is broken up by Kieran, Emma changes her mind and decides to leave with Kieran until finding one of Ms. Lang's tapes left by the killer. Kieran and Emma investigate the tape together while Kieran steals Ms. Lang's keys to sneak into house. The duo discover many things about Ms. Lang, such as her being in the same orphanage as Piper and an obsession with Emma. They eventually wind up at a party, where Kieran loses sight of Emma for the rest of the episode when she goes upstairs and finds Piper's rotting corpse.
In Heavenly Creatures, Kieran comes to Emma's house at 3:30 AM to comfort Emma after the killer snuck into her home. The two work together with Audrey to find out if Eli is the killer or not. Kieran offers to confront his cousin but Emma begs him not to out of concern for his safety, which he reluctantly agrees to. They continue to work together and find further evidence that Eli is the killer, finding Audrey's letter to Piper. Later, Kieran notices Emma and Audrey heading to the barn on their own and calls the police out of concern. After Emma is framed for Mayor Maddox's death, he tries to get to them but Acosta stops him, knowing it would only make things worse. He watches in despair as the car taking Emma drives away.
In When a Stranger Calls, Emma sneaks into Kieran's house and tells him that she and Audrey will be hiding out at the theatre. Kieran, along with Brooke and Noah meet them there and form a plan to trap the killer. The plan fails and Brooke is stabbed by the killer. The police arrive and Kieran tells Emma to run. She calls him later and begins to blame herself for everything that has happened. Kieran tells her that none of what has happened is her fault. He calls her later once she arrives at the orphanage to find Audrey who has been taken by the killer. He asks Emma where she is but she refuses to tell him because she doesn't want anyone else to get hurt. They both declare their love for one another before Emma is forced to hang up so that she can answer the killer's call. She finds Audrey shortly after but is shocked when Kieran arrives. He tells her that he tracked Noah's phone to find her. An injured Eli arrives and tells Emma that Kieran stabbed him and is the killer. Kieran denies this. Eli then reveals to a unconvinced Emma that the reason he was given the restraining order from the girl in Atlanta is because Kieran framed him. He came to Lakewood for revenge. Kieran accuses Eli of being the killer and Emma shoots him when he attempts to stab Kieran. Kieran tells Emma and Audrey that they will both feel safe again which Emma tells him is similar what the killer told her and she realises he is the killer. Shocked, Emma asks Kieran to tell her that she's wrong. Kieran confirms her suspicions by shooting Eli dead when he gets back up. Kieran explains to Emma that he was dating Piper long before he arrived in Lakewood and that they worked together during the killings. His relationship with Emma was his way of getting her to trust him. After Piper was killed, Kieran decided to get revenge and started killing alone with the idea of framing Emma and Audrey for everything. Audrey creates a diversion so that Emma can escape but she instead begins to taunt Kieran. She subdues him rather easily with Audrey's help. Although Audrey encourages her to kill Kieran, she makes the decision not to kill him so that he can rot in prison. SHe watches in pride and triumph as he is taken away by Acosta.