It’s June 26, 1954. Egon and his co-workers inspect Claudia's corpse in the station's morgue. Egon immediately recognizes her, saying that she had come into the police station before, apologizing profusely but making little sense otherwise, on the same day that the missing Helge returned. One of the other officers suggests that Egon show a photo of Claudia to Helge, to see if the young man could shed more light on just who the mysterious dead woman was. Shortly after arriving at the Doppler family home, Egon questions the boy. Helge says that while he doesn't know her, he has heard about her, calling her "the White Devil", and while he doesn't reveal his source for this information, he also claims that Claudia "wanted to kill everyone". Egon then points out that Claudia is dead, so she can't hurt anyone any longer, to which the boy responds, "...she hasn’t even started."
In 1987, Claudia is sitting at her desk in her office at the nuclear power plant, recording her research findings. When she realises that it's the day her father Egon is supposed to die, she hurriedly rushes out to see him. She continues to push him to move in with her, and Egon shows increasing reluctance to leave his comfortable apartment. Claudia, disheartened, then asks if she can come with him to his first chemotherapy appointment that day, to which Egon responds with heartfelt joy.
Martha becomes very annoyed with Bartosz and heads off on her own to Hannah’s house. While Hannah isn’t there, the future adult Jonas is. Martha, unsure initially at who he is, fears him, but he gains her trust by proving that he is the future Jonas by repeating her own words back to her, and by telling her that he left the St. Christopher medal for her. Sitting at the kitchen table he starts to explain his absence, but Martha interrupts. She takes his hand in hers and touches his forearm and face. Jonas seems surprised by her actions, and intensely heartstruck by her touch. A short time later, Katharina breaks into the house, searching for Martha. Jonas is protective, shielding her from Katharina, who is disgusted to see them together, and begins to inform Martha that she and Jonas are actually related. This information proves to be a lot to take in for Martha.
Clausen closes in on Aleksander, stating that he is looking for Aleksander Köhler, who is his brother. After some interrogation on the subject, he curtly states that "you are not my brother." It is not clear whether Clausen knows that Aleksander stole the real Aleksander Köhler’s identity, or if the man he believed was his brother had changed too drastically too believe.
Hannah uses the time machine she stole from the future adult Jonas to travel back in time to 1953, wanting to see Egon because she thinks the man accused of murdering the children at that time might be her husband. She lies when asked about her name and says that she is Katharina Nielsen. Egon, slightly suspicious at the sudden appearance of a relative, eventually lets her visit Ulrich in jail. He is at first overjoyed to see her, finally comfortable with someone from his familiar timeline, and then asks about Katharina and his children. Hannah doesn't answer, she wants to know if Ulrich could choose, more now than ever, between her or Katharina? He fumbles with his words, and then tells her what she wants to hear. But his words sound hollow and desperate, and Hannah can hear it. She turns around and tells Egon that despite a slight resemblance, Ulrich is in fact not her husband. Back in his office, he politely asks about her family, and seeing her suitcase, he wonders if she is leaving. Hannah states that she lost everything back where she came from, and is looking for a fresh start.
Jumping back to 2020, at the Doppler house, Franziska, Magnus, and Elisabeth share what they know with Charlotte and Peter, who are actually already aware of the time traveling occurring. Once Franziska realises that her parents are not surprised by the news about time travel, she gets angry that they kept this knowledge a secret.
In 1987, Egon begins to tell Claudia what he knows about time travel, and though she doesn't seem surprised or bewildered, she doesn't immediately share her own knowledge on the subject with her father. When he starts to put the facts together and realizes that the time travel is actually stemming from something in the caves, Claudia grows increasingly hostile and defensive. He stands up from his chair, indicating that he wants to call the officers at the police station and inform them about suspicious activity in the caves. At this point, they fight over the phone and Egon falls backwards, cracking his head open on the table. Though initially frightened and upset that she hurt her father to the point of almost calling an ambulance (which would have saved his life), she eventually lets him bleed out on the floor, as she remembers what the older Claudia said about heavy sacrifices. Egon’s speaks his last words to his daughter: "You are the White Devil."
After waiting several hours to ensure her father's passing, she heads home, visibly distraught, dropping her bag on the floor as she walks through the door and begins to wash the blood from her hands. A few minutes later, a young Jonas lets himself into her home, and tells her that they have to go. He knows what she did, but it also doesn't have to happen that way again. "Where are we going?" she asks, "The future," he responds.
- People are peculiar creatures. All their actions are driven by desire, their characters forged by pain. As much as they might try to suppress the pain, to repress desire, they cannot liberate themselves from eternal servitude to their feelings. As long as the storm rages within them they can find no peace. Not in life, not in death. And so, day after day, they will do all that must be done. Pain is their ship, desire their compass. All that humankind is capable of.
- Egon: Do you know this woman?
Greta: Answer the sergeant.
Egon: Were you with her maybe? Did she lock you in?
Helge: He told me about her. The White Devil.
Egon: Who? Who told you about her? The man who did that to you? The White Devil. Tell me about the White Devil.
Helge: She wants to kill us. All of us.
Egon: She's dead. She can't hurt anyone anymore.
Helge: But she hasn't even started yet.
- Aleksander: What is it?
Clausen: A copy of a document from the Marburg Registry Office, the info on your last ID before you left Marburg.
Aleksander: I've no idea how this is relevant.
Clausen: Nothing stands out?
Aleksander: No. What should stand out?
Clausen: 5' 6", I'd say. Tops. That document says 5' 8". So where are they?
Aleksander: Where are what?
Clausen: The two inches.
- Egon: You were always different. You saw the world differently from the very start. Sometimes I think that that's my problem—that I can't see the world as it truly is.
- Clausen I have no idea what's going on in this town. But I'm very certain of one thing: you are definitely not my brother.
- Claudia: What's in the caves eclipses all scientific discovery. That substance turns all we know about the universe on its head. And you want to risk all of that? For nothing?
Egon: You haven't changed. It's still all about you. You have no heart.
- Hannah: I lost everything where I came from. All I want is a fresh start.
- Jonas: I know what you did. She told me. But she also said it didn't have to happen that way again, next time.
Claudia: Where are we going?
Jonas: To the future.
- The White Devil - Der weiße Teufel is a 1930 German film adapted from the Tolstoy novella Hadji Murat, in which the titular character forms an alliance with his enemies in order to exact personal revenge.
- The Matrix - In the 1999 science fiction film The Matrix, what humans perceive as reality is actually a massive computer simulation, and a feeling of déjà vu indicates a "glitch in the Matrix."
- Among the items found on Claudia's body is a pocket sundial, which can be used to estimate time and provide direction. This is the first time such a device has been depicted on the show.
- Aleksander Köhler's height is listed as 175 cm (almost 5'9"), and Clausen estimates Aleksander Tiedemann's height at 171 cm (a little over 5'7"). It is not clear why the subtitles use different measures.
- Who wrote the anonymous letter to Clausen?
- Dietrich Hollinderbaumer as Adam
- Lisa Vicari as Martha Nielsen
- Andreas Pietschmann as The Stranger
- Maja Schöne as Hannah Kahnwald
- Oliver Masucci as Ulrich Nielsen
- Louis Hofmann as Jonas Kahnwald
- Jördis Triebel as Katharina Nielsen
- Daan Lennard Liebrenz as Mikkel Nielsen
- Sebastian Hülk as Egon Tiedemann (1953)
- Lisa Kreuzer as Claudia Tiedemann
- Florian Panzner as Daniel Kahnwald
- Stephan Kampwirth as Peter Doppler
- Karoline Eichhorn as Charlotte Doppler
- Sylvester Groth as Investigator Clausen
- Gina Stiebitz as Franziska Doppler
- Paul Lux as Bartosz Tiedemann
- Moritz Jahn as Magnus Nielsen
- Carlotta von Falkenhayn as Elisabeth Doppler
- Cordelia Wege as Greta Doppler (1954)
- Tom Philipp as Helge Doppler (1953)
- Christian Pätzold as Egon Tiedemann (1986)
- Peter Benedict as Aleksander Tiedemann
- Henning Peker as Pathologist Udo Meier
- Lea Willkowsky as Jasmin Trewen
- Leopold Hornung as Torben Wöller
- Mieke Schymura as Officer Justyna Jankowski
- → See 33 images from The White Devil at Images from The White Devil.