|Dates||???? - 2017 (died during child birth)|
|Location||North Cove, Washington|
|Episode(s)|| 12.08 LOTUS|
12.13 Family Feud
12.17 The British Invasion
12.19 The Future
12.23 All Along the Watchtower
Before all this happened, I was a cut-rate political flack in an embarrassingly unprofessional relationship with my boss. I don't know why it's me. And I don't know why it's you. But I know that we are destined for something here. Something great.
– Kelly Kline, 12.19 The Future
Kelly Kline was an aide to President Jefferson Rooney. At some point in time, the two began an intimate relationship after the death of Rooney's wife. After Rooney is possessed by Lucifer, she becomes pregnant with his child – a Nephilim named Jack.
After the sudden death of a Secret Service agent, Kelly reminds the newly Lucifer-inhabited President Jefferson Rooney that he should lead them in prayer, like he always does every morning. When Lucifer obliges, Kelly and the rest of the staff get on their knees and pray along.
The next day after a briefing, Kelly informs Lucifer that he (as Jefferson Rooney) is officially the most popular sitting president, according to a recent poll. While Lucifer is impressed by the news, Kelly tells the Secret Service agent watching them to take a break. When Lucifer asks Kelly if there was anything else, the two end up having sex. Post-coital, Lucifer learns from Kelly that they have been having an affair for sometime now, with Kelly telling him how she hopes one day they could be a couple in public. She wants for them someday to get married and have a child, remarking that Jefferson would make a good father. Later that night, after having sex once again, Kelly remarks that something was different, that she feels something has changed.
After finding that a Nephilim has come into existence, Crowley is able to learn of Kelly's relationship with President Rooney through his contacts. As Kelly finds out she has become pregnant, Crowley teleports to the presidential retreat and whisks Kelly away back to Sam and Dean's motel room. They try to explain the situation to her, which she finds hard to believe. They tell her that they know of her pregnancy and that the child is Lucifer's. When she still does not believe what she is being told, Castiel tells her that her child is an abomination and has her place her hand on a Bible, which is set aflame upon her touching it. Kelly, finally believing what is going on, agrees to help them lure Lucifer to the motel room in order to remove him from President Rooney.
As Lucifer arrives, he has the Secret Service go through and sweep the motel. When an agent finds Castiel in the closet, the angel touches his head and tells him there is no one in the room other than Kelly, and to wait in the car. After being given the all-clear Lucifer enters the motel room, where Kelly tells him that she can't keep their child. Angry, Lucifer begins choking Kelly until Sam bursts into the room and uses the hyperbolic pulse generator on Lucifer. After Lucifer is expelled President Rooney, Kelly in tears begins calling out to him. Sam and Dean have Castiel take her away while they check on the president. Sometime later, at a diner, Kelly excuses herself to the bathroom, but while Castiel is not looking, she sneaks out the back entrance and calls a taxi. By the time Castiel realizes she is gone, Kelly is already down the road. She calls him from the cab to tell him that she can't get rid of the baby. She says she can feel it inside of her and that she is still its mother, before hanging up.
At a diner in Coeur d'Alene, Idaho, Kelly orders an orange juice from a waitress, who talks to her about her pregnancy. After taking Kelly's order, the waitress walks away from her booth, her eyes glowing an angelic blue.
Later that night, Kelly is walking down a street. She looks back to see a man walking behind her, prompting her to begin walking faster and duck behind a building. She looks around the corner to see nothing, but as she sighs in relief the man reappears. She runs into an alley only to find the waitress blocking her escape, an angel blade drawn. Dagon quickly appears and orders the angels to get away from Kelly; when the male angel disregards her and attempts to attack, Dagon kills the angels with ease. After being taken to safety a startled Kelly questions what happened; Dagon explains that she is a demon and those were angels trying to kill Kelly. Dagon says that she has come to help her and her unborn child because he could save everyone. She convinces Kelly to take Dagon as her protector.
At their safe house, Kelly is lying on the couch in discomfort as Dagon brings her some food and drink. Kelly remarks she is feeling pains and demands to see a doctor, against Dagon's protests that she is fine. At the doctor's office, Kelly is told her test came back fine. The doctor seems to notice something in her sonogram but is compelled by Dagon to tell Kelly everything is fine.
Back at the apartment, Kelly is on the phone with Dagon telling her what vitamins and supplements she needs. She then receives a phone call from Sam, impersonating a doctor, asking Kelly to come back to the the office to go over some issues with her test results. As Kelly is walking towards the doctor’s office, Dean falls in alongside her, grabbing her arm and pulling her into the Impala. They drive to the junkyard where Sam, Eileen Leahy, Mick Davies, and Renny Rawlings are waiting. As Sam tries to explain how they are trying to help her, Kelly continues showing trepidation. When Renny pulls out his gun, Kelly realizes Dagon has found them. Dagon thrusts her hands in the air and Sam, Dean, Eileen, Mick, and Renny are flung away, landing heavily. Dean and Mick try shooting Dagon but bullets don’t slow her down. She throws them aside again and walks up to Kelly, takes her by the hand, and begins to walk away. Eileen fires the Colt, just as Dagon disappears, taking Kelly with her and leaving Renny to take the hit.
Back at the apartment, Dagon handcuffs Kelly to the bed. When Kelly questions this, Dagon tells her she can't be trusted after being taken by the Winchesters. Kelly responds that she was worried abut her child, but Dagon bluntly tells her that birthing a Nephilim is invariably fatal for the mother.
At a new safe house, Dagon attempts to give Kelly her vitamins but Kelly slaps them away, so Dagon force-feeds them to her. Realizing there is nothing for her to do, after Dagon leaves Kelly draws a bath and slits her wrists. However, the power of the Nephilim resurrects and heals her wounds. When Dagon returns to the basement, finding a pool of blood by the tub, she questions what Kelly did, only to have Kelly tell her "He wouldn't let me die."
As Kelly is sleeping the basement, Castiel, Kelvin, and Hozai infiltrate the house to kill Dagon and Kelly. As Dagon fights with Kelvin, Castiel goes to the basement to deal with Kelly, but is unable to kill her, instead stealing her away. As they are driving down the road Kelly questions why Castiel didn't kill her, but Castiel only tells her is trying to get as much distance from Dagon as possible.
The next morning Castiel tells Kelly the new plan is to take her to the sandbox portal where she and her child will die, with their souls ascending to Heaven once passing through. When the truck stalls, Castiel books a room at a nearby motel. In the room Kelly explains that her child's power surged through her and showed her that he is good and can do good in the world. When Kelly offers to let Castiel feel her belly, she is shown a vision of Castiel saving her and the child from Dagon at the sandbox.
Sometime later Sam and Dean track Kelly and Castiel to the motel and try to explain to Kelly their plan to extract the grace from the fetus, rendering the Nephilim human. Kelly refuses, telling them they would be taking the one thing that makes the child special. Sam and Dean suggest Castiel and Kelly come back to the Bunker where they can discuss their options. As Kelly and Castiel wait in the Impala while Sam and Dean discuss what they are going to do, Kelly takes the keys and speeds off. When Castiel questions what she is doing, Kelly tells her she is taking them to the sandbox; she tells him the child showed her that if she followed his plan, he would make sure he was born.
Later that night when they arrive at the playground, Joshua greets the two at the sandbox, but is immediately killed by Dagon. As Castiel fights with Dagon, Sam and Dean arrive but are quickly incapacitated. A bloody and beaten Castiel stands next to Kelly, who takes his hand, causing him to be given a surge of the Nephilim's power which allows him to easily stop Dagon from striking him and instantly immolate her body, killing her. Catiel then knocks out Sam and Dean and takes Kelly to the truck where he tells her the Nephilim showed him the future before they drive away.