Dr. Sarah Kinney and her friend and colleague, Kevin are leaving the Weapon X re-creation facility with a team of soldiers hot on their heels. The guards shoot at the two and Kevin stops to return fire and is shot several times. Sarah stops and turns to help and he urges her to go on without him, for X-23’s sake.
She does so and makes her way to the central security monitoring room. She shoots the guard there and disables the security cameras, in the hopes that it will give X-23 the chance to complete her final “mission” and escape with her life. Sarah says a prayer to God hoping that X-23 doesn’t die.
In her narrative, Sarah notes how her father robbed of her childhood and her innocence. She realizes that she has done the same to X-23. However, she notes that when X-23 spared the life of young Henry Sutton, it proved to her that people can change and rise above what they were forced to be and become something better.
Xander Rice emerges from the shower. He is on his cell phone speaking with a representative of Wilson Fisk about the production of additional assassins for hire from the genetic material used to create X-23. They are discussing costs when a security guard interrupts on a viewscreen to inform Rice that X-23 has escaped.
In the embryo gestation chamber, a scientist is taking readings and measurements of the developing embryos. He sees X-23 in the reflection of one of the glass globes that hold the embryos just before she kills him. Before leaving, she sets an explosive charge in the chamber. As she turns to leave, a contingent of armed guards arrive to confront her. She turns around with a grim look on her face as she pops her claws. Bullets fly as X-23 wades through the entire squad with ease.
Xander checks in on one of his science team members named Morris to see if he has seen X-23. He finds Morris dead in his room. Xander orders an understandably nervous guard to continue his search for X-23 and to check the embryo chamber first. When he arrives, he finds X-23 perched atop a pile of dead security agents.
Outside, Sarah has taken out the guard at the gate and waits anxiously for X-23. In her narrative, she mentions that once they are together they will leave this place and have the chance to start again as a real family.
Inside, X-23 enters Xander’s room. He is lying in wait and she senses him a split-second before he opens fire on her from behind. She goes down and he once again calls her a “stupid beast” and taunts her by wondering aloud if they didn’t teach her better than that. She replies that they did as she pops her foot claw and uses it to slice his weapon in half, along with the finger that was resting on the trigger. She rises and stalks over to Xander who threatens to kill her. She sheathes her claws and begins to punch him with her bare hands.
As she beats on Xander, she recalls the abuse he has heaped upon her over the years. She recalls the sneering and name-calling, the torturous surgery she endured at his hands and the mission during which Xander left her to die at the hands of AIM. Once Xander is helpless and beaten, she turns to leave. He laughs at her and says that she can’t kill him. She calls him an “animal” and leaves him there in a bloody heap.
As X-23 emerges from the building, the explosives she set go off behind her. She sees a thankful Sarah in the distance and walks towards her. As she does so, she catches a scent on the cold winter air. The trigger.
X-23’s eyes turn red as she enters the conditioned berserker rage and loses control. Sarah sees the change and wonders what’s happening. As X-23 leaps at her with her claws, Sarah flashes on her last interaction with Xander.
He touched her hair and told her to go see X-23 one last time. He set her up to die at X-23’s hands.
Sarah hits the snow and as she lay there dying, X-23 comes to her senses and sees what she has done. With her dying breath, Sarah tells X-23 that her name is “Laura” and that she loves her. X-23 takes Sarah’s hand as tears run down her cheeks. She lays down in Sarah’s lap as she did so many times and says again and again, “Please don’t leave me.”
As she lies there, the pages of Sarah’s journal are blown about. In the final sentences, Sarah once again tells X-23 that she is a child and not a weapon. She makes it clear that she thinks of her as a daughter and loves her as such. Along with the scattered pages are a passport, pages from the Pinocchio story that Sarah always read to X-23 and pictures of Wolverine and Charles Xavier.
As the facility burns, an unknown party requests a final report on the facility. It is nothing but a scorched crater. All personnel were killed and all the embryos destroyed. X-23 is identified as the sole survivor. The project isn’t a complete loss though, as someone has recovered a sample of the trigger scent used to control X-23. The unseen voice wonders where she is and is assured that she will be found.
X-23 exits a bus and steps out onto the streets of New York City. It is two years after the destruction of the facility where she was created. She is wearing a pair of fishnets, a choker and a black leather jacket with an X symbol on the sleeve.