The episode begins with a montage of key events forward and in reverse and Adam asking "'where did it all begin- is there a beginning and end or one endless loop?"
Jonas awakes in his bedroom—calmly and with no neck scar. He hurries downstairs to get breakfast, and his father (still alive) joins him. Michael becomes unsettled by the mention of that evening's anniversary party for Ulrich and Katharina and then at the sight of Jonas' yellow raincoat (which he takes as a storm is predicted)- experiencing déjà vu- causing him to drop a large container of coffee. Jonas leaves hurriedly, heading to the lake with his friends. Hannah turns her attention to Michael and encourages him to get out and come to the party but this appears to upset him. It is the day before he commits suicide, 20 June 2019 (the date Jonas asked to return to in the preceding episode- when his world fell apart).
Meanwhile, over at the Nielsen house, Ulrich tries to pressure Katharina into having sex, but is interrupted by Mikkel, who enters their bedroom claiming that he is sick. After a quick check, his mother determines that he has contracted rubella, due to the small red marks all over his body.
At the Tiedemann's, Aleksander's attention is piqued when he comes across the headline, "Murder in Marburg unsolved 33 years later. Search for two fugitive perps still on" while reading the newspaper. He ponders how an investigation can still be ongoing after more than three decades of searching.
At the lake, Martha and Jonas are siting together, when he finds a pendant with an engraving of St. Christopher imprinted on it. A short while later, he suddenly remembers that he promised to teach Grandma Ines how to use her new tablet, and hurriedly leaves.
Meanwhile, Jonas who has travelled from 1921 (via 2053) to this date and has a wound on his neck (which he covers up with his jacket) is spotted by Katharina, Ulrich and Mikkel. They are surprised he is not at the lake with the others and offer him a ride but he refuses. He observes his earlier self leave and then decides to capitalize on the situation and sits next to Martha. She is surprised he has returned so soon and says he seems different. Jonas says, "I want to tell you something. Something I've wanted to for a long time. You and I are perfect for each other. Never believe anything else", and kisses Martha deeply.
Katharina, Ulrich and Mikkel make a stop at the Kahnwald's to pick up some extra glasses for their party. Michael, watching from an upstairs window, is very distraught and anxious at seeing Mikkel, who says he needs to use the bathroom. Hannah looks at Mikkel and experiences Deja vu. Michael slowly comes downstairs out of his own curiosity, and despite trying to hide, he and Mikkel make intense, unwavering eye contact which seems to emotionally distress both of them.
Later, at the anniversary party, Katharina is in full party mode. She greets Hannah and Charlotte warmly and encourages them to dance and drink with the other guests. Funnily enough, Hannah and Charlotte have both left their husbands at home, albeit for different reasons: Michael adamantly refused to come to the party, and Charlotte asked Peter not to come, due to their current rocky relationship and his affair with Benni (who he visits). Upstairs, Mikkel wakes up feeling sick again, and after some pleading, has his mother come upstairs and lie down beside him in bed. Meanwhile Hannah and Ulrich kiss (which may be the start of their affair).
Martha also brings Jonas (present-day, pre-scarred) upstairs, and gives him back the St. Christopher's medal from the lake, which she has put on a string. She says, "I thought about what you said at the lake," though he doesn’t know what she means because she is referring to what the alternate Jonas had said to her after he left. She also tells him "I think you're right," before kissing him and ultimately results in them having sex.
The time-travelling (scarred) Jonas goes home and is discovered by his father who thinks he has left the party early. Jonas hugs him deeply and tearfully says he knows that he is Mikkel Nielsen and begs him not to hang himself. He shows him his suicide note. Michael says he has no idea what he is talking about. Jonas asks him about how he disappeared and he responds that he was with Jonas, lost him at first but then Jonas took him back to the cave and left him there alone. Jonas says he never did that but an alternate (scarred) Jonas is shown stepping in, taking Mikkel. Michael suggests he has in fact not come to stop him kill himself or he will not be born and that his role is greater than he thinks, as he himself said. Claudia then enters and says she is opposed to Adam, who has brought him there to ensure everything happens as it always does. She says she has seen the world without Jonas and it isn't what he expects. Jonas will have to fight himself/Adam. Everyone has to make sacrifices, including his father. She leads him back to the cave while Michael writes his suicide note.
A middle-aged couple approaches Adam, who still has the St. Christopher's medal, "You could have told him what his function is," the man says. " Magnus, We all have to make sacrifices," states the woman.
- Tannhaus (voiceover): Where did it all begin? Where did things begin? In the past? In the future? Who can say where it began? Will we ever be capable of knowing the origin of all things? Or is there still an origin before that? And before that? And before that? Do beginning and end even exist? Or is it all connected in an endless loop, and are "beginning" and "end" just different words for one and the same moment?
- Franziska: Magnus?
Magnus: You weren't moving and I… I… I thought you were dead. He said there was a dead body there.
Franziska: Still plenty alive.
- Martha: Weren't you leaving? Everything okay?
Jonas: I thought I had more time. Why do people say that anyway? "To have time." How can you have time when it clearly has you?
Martha: Has something happened? You're different somehow.
Jonas: I wanted to tell you something. I've wanted to for a long time. I think we're a perfect match. Never think anything else.
- Hannah: Where's Peter?
Charlotte: Summer cold. And Michael?
Hannah: Something similar.
- Jonas: The night you vanished, you were there and then suddenly gone. Did you go back to the cave? How did you find the passage there?
Michael: I didn't find it, someone showed it to me.
Michael: You.… We ran. Then I lost you. I turned around and you were gone. But suddenly you were back again.… You said there was something there, in the forest. Something evil. And that we had to return to the cave. You brought me all the way to the door, and through the tunnel. I was so afraid. But you held my hand. And then you said, "We have to stay here, all night, but when morning comes everything will be all right." And when I woke up you were gone. All these years I've tried to understand why you did that. But then, at some point it all just faded away. It became ever more unreal, like a dream.
Jonas: But that's impossible. I never did that.
Michael: I saw myself today. Mikkel. It's all returning. That coat, you—as if it's all falling into place. Maybe you're not here to stop me at all. But rather to show me what it is I have to do. Maybe you only showed me the letter so I know what's in it, so I go and you live.
Jonas: No, that can't be. That can't be! He told me I could stop the origin. If you don't kill yourself, none of the rest will happen.
Michael: But if none of the rest happens, you won't be born. And maybe your role in all this is much greater than you think, and perhaps I'm just a small part of a huge cancer that is much greater than any of us can imagine.
Jonas: Someone has said that to me before.
- Jonas: Are you with Adam?
Claudia: There are two sides out there. He is the darkness. I don't follow him, I follow the light. He lied to you. He brought you here to trigger everything so it happens as it always has.
Jonas: No, that can't be. Adam wants this too.
Claudia: No, he does not. He doesn't want to fix things. He wants to destroy them forever. Your role in all of this is much greater than you believe. Only you alone can put an end to all this.
Jonas: What does that mean?
Claudia: We're at war, and you have to wage it against yourself—against Adam.
Jonas: But if I don't exist, if I'm not born, then Adam won't exist either.
Claudia: I've seen the world without you. Believe me, it isn't what you're expecting. There are times in life when you must see that the decisions you make affect more than your own destiny. This isn't just about you and Mikkel, this is about everyone—your mother, your friends, Martha. You alone can save them.
Jonas: What does that mean?
Claudia: We all have to make sacrifices. Your father must make sacrifices too.
- Ulrich: Is this the apocalypse?
Hannah: A bit disappointing. I imagined it being louder. More glaring.
Ulrich: If the world ended tomorrow and everything started anew, what would you wish for?
Hannah: A world without Winden.
- Rubella (also called "German measles" although it is not related to measles) is a highly infectious childhood disease marked by a mild fever and red rash. Since the development of a vaccine in 1969, it has been eradicated in the Americas and Australia, but not Europe. In real life, there were 20 reported cases of rubella in all of Germany in June 2019. Dengue fever, which Mikkel guesses he might have, is similarly marked by a fever and rash but is a tropical disease transmitted through mosquito bites.
- This is the only episode of Season 2 with scenes from June 2019. Since Jonas arrives from November 1921, the Sic Mundus portal appears to be capable of transporting at intervals other than multiples of 33 years.
- It is no surprise the Tiedemanns skip the Nielsens' party, given the longstanding hostility between the couples. The Tiedemanns do not exhibit any outward disapproval of the Nielsen children, however, and so rather than forbidding Bartosz to attend, it may be that Bartosz felt obligated to stay at home out of family loyalty, despite a clear longing to be there.
- This is the only episode of Season 2 where the elderly Jana and Tronte are seen.
- The words Ulrich and Hannah exchange in the Nielsens' backyard are the same as the conversation they had at the bus stop in 1986 in "Past and Present," but spoken by the opposite parties.
- We frequently are shown Jonas waking in his bedroom. Usually he has just had a nightmare and is very anxious. This is the only time he wakes up relaxed—before his world fell apart.
- We switch between the contented, timid Jonas, prior to his father's suicide, to the time travelling Jonas, who appears worried and anxious.
- Now knowing that their time together is limited ("Ï thought I had more time" he says to her), older Jonas makes his feelings toward Martha far clearer than his earlier self.
- It is apparent from Season 1, Episode 6 that time travelling could only be accomplished with a lot of guidance. Therefore Mikkel would have required guidance from someone to find his way through the portal to 1986- Jonas, just as older Jonas gave younger Jonas guidance. Jonas in guiding Mikkel to 1986 preserves the events as well as his own existence. He appears to have different objectives to his younger self, who wanted to bring Mikkel back to 2019.
- "Ultimate fist bump" appears to be the regular connection between Mikkel and Jonas, seen in episode 1 and in the meeting in the car and used again by Jonas when he meets his father to indicate he knows he is Mikkel.
- Jonas is offered a lift by the Neilsens, similar to Hannah and her father in 1986 (his parents and grandparents), refusing both times.
- The Kahnwald's and Neilsen's were friends but Hannah had not recognized Mikkel, who she had met 33 years ago.
- It seems that the recurring dream Jonas and Martha both have that they have sex is based on a memory, not just a fantasy or nightmare.
- Jonas attempts to stop his father from killing himself but may well have actually brought it on. The yellow jacket, the encounter with Mikkel and then Jonas appear to jog his repressed memory of his time travel and true identity (as described in his suicide note). Had Jonas not appeared and brought it up, would Michael have continued to suppress his real identity and never have suicided, appearing to not know anything about it? Jonas believes this is where all the bad things began and stopping it will stop everything else but is it? Is there a beginning or is it all part of an endless cycle? Similarly, Ulrich tries to stop Helge but may well have caused him to do what he does. Attempts to change the past just appear to make it the same. Claudia says everyone has to make sacrifices. Did Michael kill himself so Jonas could carry on? His note was not to be opened until after Mikkel had travelled back to 1986. In Season 1, Episode 5 the Stranger (older Jonas) tells (younger) Jonas his father saved his life: perhaps by killing himself so he could live.
- In the preceding episode Adam says a man lives three lives: The first ends with the loss of naiveté, the second with the loss of innocence, and the third with the loss of life itself. We appear to see Jonas at stage one and two.
- Louis Hofmann as Jonas Kahnwald
- Sebastian Rudolph as Michael Kahnwald
- Maja Schöne as Hannah Kahnwald
- Lisa Vicari as Martha Nielsen
- Oliver Masucci as Ulrich Nielsen
- Jördis Triebel as Katharina Nielsen
- Daan Lennard Liebrenz as Mikkel Nielsen
- Peter Benedict as Aleksander Tiedemann
- Deborah Kaufmann as Regina Tiedemann
- Karoline Eichhorn as Charlotte Doppler
- Stephan Kampwirth as Peter Doppler
- Moritz Jahn as Magnus Nielsen
- Paul Lux as Bartosz Tiedemann
- Gina Stiebitz as Franziska Doppler
- Walter Kreye as Tronte Nielsen
- Tatja Seibt as Jana Nielsen
- Lisa Kreuzer as Claudia Tiedemann
- Anton Rubtsov as Benni
- Dietrich Hollinderbaumer as Adam
- Wolfram Koch as Unknown Man (1921)
- Carina Wiese as Unknown Woman (1921)
- → See 54 images from An Endless Cycle at Images from An Endless Cycle.