Sepp Mall tells the story of two pairs of brothers, dealing with mutual misjudgment, jealousy, love, and guilt. The first part revolves around the two unequal Stocker brothers: one is a self-confident adventurer, while the other is a more reserved nurse. Together, they embark on an expedition through the Death Desert of Takla Makam, where their mutual misjudgment nearly leads to disaster. The second part focuses on Zeno Steiner, who believes he was partly responsible for his brother's death years ago. When he encounters a "resurrected" version of his brother, Zeno is forced to confront his past.