An essential recap of everything that's happened in 'Dark' so far

In the town of Winden, Germany, there are several families who are all interconnected thanks to a 33-year-cycle of trauma. The cycles take place primarily in the years 2019-2020, 1986-1987, and 1953-1954.

Jonas Kahnwald is a teenager when we first meet him in the pilot episode of "Dark."

Claudia is an adult woman who has harnessed the power of time travel and is guiding Jonas through learning about it.

Martha is a teenager who Jonas loves — but they're relationship is complicated.

Martha's little brother, Mikkel, goes missing in the pilot episode of "Dark." He time traveled to 1986 and got stuck there. So Mikkel changes his name to Michael, grows up, gets married, and eventually has a child: Jonas.

Mikkel dies by suicide just a few months before his younger self goes missing in 2019. It's a trippy paradox.

There are multiple devices that have been built and changed hands over the years that help maintain the loop of time travel. One of those is a tunnel located in a cave system in Winden, which acts as a passage between 1953, 1986, and 2019.

There's also a device which seems to activate a wormhole, or trigger an apocalyptic explosion.

Throughout season one and two of "Dark," Jonas works with either Adam or Claudia to seemingly attempt to alter or change the cycle of events that keeps happening.

But we don't yet know who created this notebook. It appears sometimes to be in Noah's possession, and other times to be in Claudia's or Adam's.

There was an accident at the power plant which led to the creation of the wormhole material known as the God Particle.

In season two, we learned that a mysterious figure named Adam had been leading a group of cult-like people in the quest for creating a "paradise" or world without time.

Adam says at one point that his travels through time led to his changed appearance.

We don't yet know exactly how Jonas transformed into Adam, not just physically but also mentally. His goals seems opposed to that of young Jonas, who wants to simply end the horrors and save his friends and Martha.

You can read our full list of unanswered questions left before season three of "Dark" here.

Passing himself off as a priest, Noah was responsible for the kidnapping and murder of many children. He claimed to be working for the side of "light," aka in opposition to Claudia.

Thanks to Noah's ability to time travel, Noah and Elisabeth met when they were both young. They grew into adults between the year 2019 and 2053, and along the way had baby Charlotte.

But someone took baby Charlotte and placed her back in time, so that Charlotte grew up throughout the '80s and had a family of her own — eventually giving birth to Elisabeth.

Again, this is a trippy paradox.

Noah shoots and kills the older Claudia, believing her to hold the answer to Charlotte's location. But she didn't.

When Noah went to confront Adam, he was shot and killed by a woman named Agnes (his sister).

Her husband is Peter Doppler, the son of Helge (a man who worked with Noah starting at a young age).

Peter wound up learning the truth about time travel and the mysterious bunker that was used to hold Noah's captives and test a time travel device.

They had a notebook (brown leather with a trinity knot symbol on it), which contained detailed information about the three time cycles and time travel.

We don't know how Charlotte got to be in Tannhaus' custody, but we do know that he raised her and she never knew who her parents were.

In season two, Noah turned up and revealed to the adult Charlotte that he was her father.

Jonas ended season one by accidentally traveling to the year 2052. Once there, he realized that his middle-aged self had set off an apocalyptic event. All Jonas wants is to get back to the year 2020 and somehow undo all the disaster.

He's caught by Elisabeth — who is middle aged herself by 2052 — and nearly hung to death. Elisabeth changes her mind at the last moment, leaving Jonas with a gruesome scar around his neck.

Thanks to Silja, Jonas is able to travel back in time. That's when he goes back to 1921 and encounters his older, scarred self: Adam.

Jonas travels forward in time to June 20th, 2019. But when he confronts his father, we realize that the only reason why Mikkel/Michael ever died was because Jonas came and told him about his death, effectively giving him the idea. Another trippy paradox.

Claudia has the younger Jonas go back in time, to 1987, and show her younger self the passageway in the Winden caves.

The younger Jonas is primarily with Claudia. The middle-aged Jonas, known in season one as "The Stranger," has been talking to his own mother Hannah and Mikkel's mother Katharina.

In season one, Mikkel's father (and Katharina's husband) Ulrich traveled to 1953 to attempt to prevent Mikkel from ever disappearing. He attacked the young Helge Doppler, and was arrested and jailed.

Hannah has always had a vindictive and manipulative streak. She was jealous of Katharina and Ulrich's relationship when she was younger, and falsely accused Ulrich of sexually assaulting Katharina as an attempt to ruin their relationship.

Realizing Ulrich's heart lies with his real family, Hannah allows him to stay imprisoned in the past. The final scene of her and young Egon Tiedemann (who is Claudia's father) implies that Hannah plans to stay in 1954 and possibly start a new affair.

Doris began a romantic relationship with Agnes Nielsen when she came to stay in their house. Agnes brought her son, Tronte, who started his own close relationship with young Claudia.

Katharina is desperate to find both her son (Mikkel) and husband (Ulrich). She goes into the Winden caves and through the passageway in the final episode of season two.

Noah claims the letter is from Martha. We didn't see what was written in it, but whatever it was shook Jonas. He said it couldn't be real.

Noah tells this Jonas to save Martha and their friends, and to continue the next cycle so that Martha can live.

But Martha escapes. She goes to Jonas' house, and then the young Jonas finds her there. After many years of loving one another but never managing to actually be together, Jonas and Martha kiss.

Adam (who, again, is older Jonas) tells his younger self that the pain of Martha's loss is what will eventually help him become the man he's meant to be.

This new Martha, who has bangs and shorter hair, tells Jonas he has to come with her. She also says the question isn't from "what time," but from "what world." This introduced a whole new slew of questions about the potential for multiple worlds and multiple versions of the characters.

You can read more about the major events in the season two finale in our long explainer here.

Bartosz is Claudia's grandson, and Martha's ex-boyfriend (and Jonas' once-best-friend). Magnus is Martha's brother. Together with Mikkel, the three of them are Ulrich and Katharina's kids.

Franziska and Magnus started a romantic relationship in the first season of the show.

Using one of the time traveling machines, Jonas disappears the four of them from Winden in 2020 — but we don't yet know where they went.

A wormhole opens, and she sees her daughter/mother Elisabeth in the year 2053 through the opening. They reach to touch hands, presumably transporting themselves somewhere (or somewhen) new, just like Jonas did in the season one finale.

So all five of them are presumed to have survived the Apocalypse, though again, we don't know for certain yet.

There are many, many other details throughout the first two seasons you might want to refresh your memory on. For more, you can visit the official "Dark" website which lists all of the main characters and their overarching storylines across both seasons.

• Read more:
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• The full trailer for 'Dark' season 3 will leave you both more confused and excited than ever for the series conclusion