In The Nurse, Pernille grows suspicious of her competent coworker, Christina, and soon discovers that Christina is not the good nurse that everyone believes her to be. Christina Aistrup Hansen is played by Josephine Park.
When Pernille starts working at Nykøbing Falster Hospital as a nurse, she is trained by the hospital’s most skilled nurse, Christina, who sometimes even knows more than the doctors.
Initially, like everyone else, Pernille is also impressed by Christina, but as she grows close to Christina, she realizes that something is not right, which makes her investigate on her own.
Pernille realizes that Christina is not what she seems to be when she overhears her telling the other nurses about an incident that involved her changing a patient’s tubes and getting their blood all over her face.
What is strange is that this never happened to her; it was Pernille who changed the tubes and got the blood on her face. This is the first time Pernille catches her lying, but it is not the last.
Another time, Christina tells Pernille and the other nurses that she got into a car accident with her daughter and that her car is completely wrecked. However, on the same day, Pernille comes across Christina’s car and finds it in perfect condition.
Pernille also hears from another nurse that Christina once slept with Niels Lundén, the chief physician Pernille had started dating. This makes her uncomfortable until Niels assures her that this is just a rumor. Perhaps a rumor that Christina is responsible for spreading.
Pernille is not the only one who knows that Christina lies a lot. Christina’s ex-partner also seems to be sick of her lies and is not very kind to her.
Christina’s conversation with her ex-partner reveals that Christina has rushed her daughter, Nanna, to the ER more than once, claiming that Nana has a stomach ache, but Nanna told her father that she does not remember having a stomach ache when her mother took her to the ER.
When Pernille goes to Christina’s house, she finds patient records there. Christina tells her that she took permission before taking them and that she studies them to get better at her job because her sister died of leukemia and she could not save her.
When Pernille catches Christina lying and making up stories more than once, she starts feeling uneasy around her. Additionally, she is warned by another nurse that Christina cannot be trusted, as she always wants to be in the spotlight.
Finally, during an emergency, Pernille starts CPR on a patient, but Christina pushes her aside, straddles the patient, and starts doing chest compressions in a way that makes it seem very sexual to Pernille.
She discusses this with Niels, who tells her that Christina is just passionate, but that does not put her mind at ease. She starts noticing that the medicines have been going missing from the medicine room.
She also speaks to another nurse named Katja, who also thinks that Christina’s shifts are so hectic, while the other shifts are simply boring. Pernille’s discomfort around Christina grows to the point that she asks the head nurse to switch her shifts.
When a stable patient, John, who had come to the hospital for urinary retention, goes into a sudden cardiac arrest and mysteriously dies during Christina’s shift, Pernille thinks that Christina might have something to do with it, as John never had heart problems.
As Christina had signed off on 22 deaths in just a year and a half, Pernille becomes convinced that Christina has been killing patients. She talks to Katja and Niels, but they both dismiss her because her theory sounds insane.
However, Niels comes to believe her later on when he realizes that John’s death does not make sense. They investigate together and learn that when Christina left M130 to work in the ER3 ward, the mortality rate there fell from 90 deaths a year to 50.
An old colleague of Christina’s, Ida, from M130, also had the same experience as Pernille while working with her. She complained to the head nurse back then, but no one took her seriously.
Ida tells Pernille about a patient, Arne, who had died mysteriously during Christina’s shift. The hospital conducted a root cause analysis and found massive doses of morphine and diazepam in his blood.
This brings Pernille and Niels to the conclusion that Christina injects the patients with diazepam to induce cardiac arrest. She then saves them to look like the star nurse who always knows more than the doctors.
They believe that Christina’s aim is not to kill the patients but to save them from dying to earn praise and admiration from others. This is her way of staying in the spotlight, but it has cost so many innocent patients their lives.
Niels tells Pernille that they cannot go to the police without proof, as in the end, it will be her word against Christina’s, and no one will believe Pernille. The case will be dropped, and Pernille’s life will be ruined because no one will hire her after this.
Pernille needs to catch Christina doing something to the patients, so she takes a night shift with Christina. She keeps an eye on her all night, but despite that, she fails to catch her red-handed and three patients die.
Finally, when Pernille realizes that the alarm in the room of a patient, Maggi, whose condition had gotten worse throughout the night, is off, she quietly sneaks into the room and sees Christina injecting Maggi with something.
Christina panics seeing Pernille there, so when Pernille leaves, she sets off the alarm before the cardiac arrest occurs. The doctor cannot figure out what is wrong with Maggi, as the patient’s heart is still beating but she is unresponsive.
Pernille asks the doctor if this could happen to someone who has been given diazepam. The doctor decides to give Maggi the antidote to diazepam, which ends up saving Maggi’s life.
The next day, Pernille, along with Niels, contacts the police to report Christina’s crimes, as she caught Christina in the act. The police arrest Christina for committing three murders and the attempted murder of Maggi.
While Pernille is ostracized at work for filing a complaint against Christina, she manages to save the lives of patients who would have become Christina’s victims in the future. Christina, who murdered her vulnerable patients instead of saving their lives, eventually gets sentenced to 12 years in prison.