In "Dark" Season 1, Episode 2, titled "Lies," the mysterious disappearance of Mikkel Nielsen intensifies the already palpable tension in the small German town of Winden. As the community grapples with Mikkel's absence, police officer Ulrich Nielsen, Mikkel's father, becomes increasingly desperate, especially given the haunting parallels to his brother Mads' unsolved vanishing 33 years prior. Determined to uncover the truth, Ulrich's investigation leads him to the Winden Caves, where he discovers a locked door connected to the local nuclear power plant. His request for access is denied by the plant's director, Aleksander Tiedemann, further fueling Ulrich's suspicions. Meanwhile, a disoriented Mikkel awakens in the Winden Hospital, only to realize that he has inexplicably traveled back to the year 1986. This episode intricately weaves themes of time travel and familial bonds, setting the stage for the complex narrative that "Dark" masterfully unfolds.