Biologist Valerie Lemke dies after a visit to a glacier. Dr. Hartmann quickly determines that she was pushed into the abyss. Jerry and Sophia investigate among her colleagues. Dr. Magda Hansen was a rival for Professor Gruber's affections, while Christian Wenzel was an environmental activist and a jilted lover. Even pharmaceutical manager Oliver Gross falls under suspicion because Lemke's research on blood algae was commercially lucrative.

Steelworks owner Annette Loibl is horrified – her blind daughter Charlotte has been kidnapped. The investigation focuses on Vroni Ketschauer, who was fired by Annette's partner, Ferdinand Mitterhammer. Sophia goes undercover as a security officer at the Loibl steelworks. She feels sorry for Vroni Ketschauer, a single mother struggling financially and harboring a secret, and is carried away by a rash action… Meanwhile, new colleague Franzi helps the grateful detectives Strasser and Paulsen install a call trace.