Season 1: Martha, Mikkel's sister, deals with the fallout of her brother and then her father's disappearance during this season, as well as a love triangle between her, Jonas, and Bartosz.
Season 2: Martha spends much of this season dealing with the same issues. Aside from realizing that she's in love with Jonas (though she doesn't realize she's his aunt!) and discovering time travel from Bartosz, not much happens with her. Then, moments before the apocalypse, Martha is with Jonas when Adam appears and shoots Martha, killing her. Another minute later, Adam is gone, and a second Martha (with bangs!) shows up and tells Jonas they need to go, pulling out a small gold time machine that takes them away.
- Adam's World:The Martha from this reality doesn't appear in this season, as she's dead.
- Eva's World: After saving Jonas from the apocalypse, Martha leaves him in "her world," off to complete her next task. Jonas then meets the same Martha, but from days before, and he teaches her about time travel, his world, and her fate there. Meanwhile, future young Martha travels back to 1888 to see adult Jonas and facilitates the loops before heading to 2053, where she's essentially held captive by Adam. Adam explains to her that her older self is the reason the loops begin, as she is the catalyst for Jonas and Martha conceiving a son, who is "the origin." Once Adam learns the truth about breaking the loops, Martha travels back in time with Jonas to stop H.G. Tannhaus's son from ever dying, thus eliminating her existence.
- Origin World: Because Agnes can't be born without time travel, Martha can't exist as her great-granddaughter.