Season 1: The 1986 Aleksander (Béla Gabor Lenz) is a bit of a mystery, to be honest. He pops up at just the right moment to save Regina as a teen (two fake passports in his possession), and the pair later marry and have a son named Bartosz. By 2019, he's grown into a hardened businessman (played by Peter Benedict) who is in charge of the nuclear plant that Regina's mother, Claudia, used to run.
Season 2: After being questioned by Investigator Clausen as to why he took his wife's last name, Tiedemann, Aleksander tells the detective that his original surname was Köhler. Although, that is also not the truth, as Investigator Clausen reveals that his original last name is Köhler and that his brother, Aleksander Köhler, has been missing since 1986.
- Adam's World: We get a glimpse of young Aleksander comforting Regina following her mother's disappearance, but that's about it for Aleks in this reality.
- Eva's World: In this reality, Aleksander becomes a widower in September of 2019. He is being pursued by Charlotte Doppler, who wants to know about the power plant on the night of Mads's disappearance in 1986. He's also being blackmailed by Hannah, who knows about his true identity, which leads him to ultimately tell Bartosz the truth: his name is Boris Niewald and he murdered someone in 1986 (but don't worry, it was "an accident!").
- Origin World: It's completely unclear what happens to Aleksander/Boris in the origin world, but we sure hope he didn't become a murderer this time around.