If a 'clock ticking' sound is heard during scene transitions, it means that timeline has also changed.
In the third season, you can tell the three worlds apart by looking at the aspect ratio of the scenes. The origin world has the widest aspect ratio.
Most of the forest scenes were shot at Fahrtechnikakademie Kallinchen near Berlin. This is an old military test site from the East German era.
Throughout the series, a different song is usually used in each episode. These songs are generally heard 10-12 minutes before the episode ends. During the songs, the episode in a sense summarizes multiple timelines, and the lyrics are usually related to the context of the episode.
In almost every interior scene, some kind of clock (wall clock, wristwatch, alarm clock) is visible.
The unforgettable opening song 'Goodbye' belongs to German musician Apparat. This song has been used in various film trailers and TV shows. One of its most notable uses is in the climactic scene of the 'Face Off' episode, the season 4 finale of Breaking Bad.
In the third season, zoom transitions mean the scene is switching between two worlds.
In the third season's title sequence, the letters 'D' and 'R' in the show's name are written mirrored; this references the season's dual, alternate worlds.
Nikolaus Summerer's cinematography has a distinctive personality, with either an object or a shade of yellow present in every frame.
Neither the 'WIN' (for Winden) German license plate nor the German state shown by the 3 fir trees on the police emblem exists in real life. This was done to imply that the story could take place anywhere.
The scenes outside the cave were shot near the village of Saarmund in Brandenburg, Germany. Because the region's geology consists only of underground moraines, there is no natural cave, and therefore an artificial entrance was built. This 'cave' was only 30 feet deep.
All the interior sets in Eva's world (season 3) are reversed; for example, the stairs of Martha's house (the reverse of the stairs of Jonas's house in the other world).
The first season lasted about 150 shooting days.
It was shot in the Univisium aspect ratio of 2.0:1.
Principal photography began on October 18, 2016, in and around Berlin.
The production used a 'color coding' system for the three main timelines: 1953 has a brownish/yellow tone, 1986 has blue and orange tones, and 2019 has a cold, desaturated gray-green look.
Composer Ben Frost created the soundtrack using a mixture of traditional strings and industrial sounds, including the sound of a burning piano to create a sense of unease.
The production had to account for the child actors' growth; they shot most of the 'young Mikkel' scenes as quickly as possible so that no noticeable growth spurts occurred between episodes.
The prop used for H.G. Tannhaus's time machine was handmade and included parts from real vintage clocks and 1920s machines.
The 'Yellow Raincoat' was a deliberate choice to make Jonas stand out against the dark, muted colors of the German forest, just like the 'red coat' in Schindler's List.
The 'Sic Mundus Creatus Est' tablet and the bunker were built as physical sets to allow the actors to interact with the environment without relying on green screen.
The 'cave' entrance was a set built in the forest; the interior cave scenes were shot in a studio or in various natural limestone caves in Germany.
The series' famous 'Winden' does not actually exist; the forest scenes were shot at an old military firing range outside Berlin, and this location provided a naturally eerie and untouched landscape.
Most of the characters were given specific flaws to help viewers distinguish them not only in their own world but also across timelines. Jonas and Martha's son, the Unknown, has a cleft lip (sometimes also called a harelip).
The casting process was extremely meticulous because the actors playing the same character in different time periods had to match exactly in facial structure and ear shape.
Most of the 'young' and 'old' actors are not related in real life; the only exception is the real-life father and son who play the trio of the 'Unknown' in season 3.
Carina Wiese (Franziska Doppler) and Sylvester Groth (Inspector Clausen) appeared together in the series Deutschland 86 (2018), set in 1986.
It is the first German series made by Netflix.
The series' creators, Baran bo Odar and Jantje Friese, were not keen on the offer when Netflix asked them to adapt their 2014 film Who Am I into a series. Instead, inspired by the series The Missing (2014) and a time travel film, they combined the two ideas and eventually created Dark.
Just before the second season was released, in June 2019, the series was renewed for a third and final season.
Netflix greenlit the first season of the series in February 2016. The second season was ordered in December 2017.
The series' timeline was so complex that Netflix released an official interactive website to help fans follow the characters and avoid spoilers.
Every season was planned before even the first episode aired; the writers knew from the very beginning how the series would end in the 'Origin World'.
Director Baran bo Odar and producers Max Wiedemann and Quirin Berg had previously worked together on the film Who Am I (2014).
Dark was Netflix's first original series shot in German, and its global success paved the way for other international productions such as Squid Game and Money Heist.
The series actually came about when creators Baran bo Odar and Jantje Friese were asked to turn their 2014 film Who Am I into a series; they turned down the offer but used its 'hacker' mystery elements to lay the foundation for Dark.
The tattoo on Noah's back and the Emerald Tablet seen in the local hospital photograph in the 1986 version are part of a collection of Greco-Egyptian mystical "wisdom texts" from the 2nd century known as the "Hermetica". This text deals with subjects such as alchemical experiments, transformation and the creation of the universe. More importantly, it discusses the idea that great and small actions are interconnected and influence one another, which is one of the series' main themes. Conspiracy theorists also claim that the text is far older than the language it contains, suggesting it came from an unknown place, or even from aliens or time travel.
In season 2, episode 1, Noah's book contains a note dated June 27, 2020: "The Beginning of the Last Cycle". This date is also the release date of the final season, season 3.
The Triquetra, seen on the cover of the Unknown's diary and throughout the series, implies multiple revelations as the series progresses. In the first two seasons, it marks the relationship between the three main timelines (1953, 1986 and 2019). In the final season, which deals with two separate interconnected worlds, it implies the existence of a third world. The viewer only learns of the third world's existence in the final episode. This third world is the world of Origin.
The series frequently references the Twix chocolate bar, which was sold in Germany under the name Raider from 1976 to 1991. When Ulrich finds the chocolate called Raider, it is implied to be from the 1980s.
The date November 12 is also a critical date in Back to the Future (1985); it is a day on which many time-travel decisions and actions coincide.
The main motif of the series' music imitates the "Doppler effect" (a shift from high pitch to low pitch); perhaps a reference to the centrality of the Doppler family in the story.
The symbol on the cover of H.G. Tannhaus's book is the Penrose Triangle; an "impossible object" optical illusion created by psychiatrist Dr. Lionel Penrose and his son, mathematician and Nobel laureate Sir Roger Penrose. Roger Penrose is the author of one of several interpretations of quantum mechanics that Tannhaus explains to the viewer in season 3.
The premiere date of season 3 on Netflix is June 27, 2020; this is the "end of the world" date in the series.
One of the dead children's T-shirt reads "Atomenergie, nein danke"; this was the slogan of the German anti-nuclear movement in the 1980s.
The initials of H.G. Tannhaus, the character who invents time travel, refer to H.G. Wells, the author of the famous 1895 novel "The Time Machine".
In the first episode of season 3, when Jonas enters the classroom, Martha is seen repeatedly drawing the infinity symbol while Bartosz talks about timelines. This is a small hint at the ultimate truth she will learn.
The song young Ulrich listens to is 'Pleasure to Kill' by the German metal band Kreator (from their 1986 second album "Pleasure to Kill").
The shape of the nuclear plant's cooling towers is the same as the Einstein-Rosen Bridge discussed in the quotations in H.G. Tannhaus's book "A Journey Through Time".
The game Bartosz and Jonas play in season 1, episode 5 is Surge by the German developer Deck 13. The game can best be described as a sci-fi Dark Souls, but it has no co-op mode. This was probably a tech demo provided for the series.
The black T-shirt Ulrich wears in the scene where he has sex with Katherina in the school locker room in 1986 (1x05) and later when he gets out of prison (1x09) features an edited version of the official logo of the short-lived underground Swedish black-metal band Morbid. This band was formed at the end of 1986 and was almost unknown outside the Swedish metal underground before the release of their first demos in 1987; moreover, the specific version of the logo on which Ulrich's T-shirt is based was not known until the demo's 1994 reissue; therefore Ulrich's T-shirt can be seen as anachronistic (or from an alternate universe).
Fans of the series immediately noticed the many similarities between Dark and the video game Bioshock Infinite and started a Reddit thread based on it. It is possible that the creator and/or the writers were inspired by the game, but nothing has been confirmed.
Dark is often called a "Greek Tragedy" in the guise of science fiction because it focuses on the idea that people are slaves to their own desires and cannot escape their "Hamartia" (fatal flaw).
The "33-year cycle" is based on the real-life lunisolar cycle; the lunar and solar calendars roughly align every 33 years.
The "St. Christopher" medal appears at almost every important turning point in the series and serves as a physical anchor for the "bootstrap paradox".
The "Emerald Tablet" text (Sic Mundus) is a real ancient hermetic text that has fascinated alchemists and mystics for centuries.
Agnes Obel's song "Double Life", used in the season 1 montage, became the unofficial anthem of the series' theme of hidden identities.