Dark series explained in short

The Dark series is a set of German science fiction television series created by Baran bo Odar and Jantje Friese. The series consists of three seasons, with the first season, simply titled Dark, premiering on Netflix in December 2017.
The series is set in the fictional German town of Winden and follows the lives of several families, including the Nielsens, the Dopplers, and the Tiedemanns, as they become entangled in a web of secrets and lies that span several generations. The first season introduces viewers to the town of Winden and its residents, as well as a mysterious cave system beneath the town and a strange, supernatural event that takes place in the town's nuclear power plant.
The second season, titled Dark: Season 2, premiered on Netflix in June 2019 and continues to follow the lives of the town's residents as they try to unravel the mysteries of the cave system and the supernatural event at the power plant. The season also introduces viewers to new characters, including a group of time travelers from the future, who are attempting to change the course of history.
The third and final season, titled Dark: Season 3, premiered on Netflix in June 2020, continued to follow the lives of the town's residents as they try to make sense of the events that have taken place and the secrets that have been revealed. The season also ties together the various threads and storylines from the previous seasons, and finally reveal the fate of the characters and the town of Winden.
Throughout the series, viewers are introduced to a complex and multilayered narrative that is centered around time travel, and how it can be used to change the past and potentially alter the future. The series also deals with themes of guilt, grief, and redemption, as well as the power of love and family.
One of the most notable elements of the series is its use of non-linear storytelling, which jumps back and forth between different time periods, including the years 2019, 1986, and 1953. This allows for a deeper exploration of the characters and their relationships, as well as the way that their actions in the past can have a profound impact on their present and future.
Additionally, the series explores the concept of fate and free will, as the characters struggle with the idea that their actions may be predetermined, and that they may not have the power to change their own destinies.
Overall, the Dark series is a complex and thought-provoking science fiction television series that deals with a variety of themes and ideas. Its use of non-linear storytelling and time travel elements adds depth and nuance to the narrative, making it a unique and memorable viewing experience.