YouTuber Nana dies dramatically during a live stream of her channel. Her subscribers and her boyfriend Crazy Alex are deeply touched. With Felix's help, Tremmel and Elena try to catch the murderer.
A pigeon keeper is found dead inside a cage with his birds. Meanwhile, Elena is working with Felix's arch-nemesis, professor Schweizer, and Tremmel is flirting with Felix's mother.
To familiarize his students with the principles of physics, Felix uses a sophisticated method to steal from ATMs with compressed air. Elena and Tremmel investigate a case where a safe-cracker used the exact same method as Felix's.
A camper fishes out a rubber boot containing a foot in a state of decay. Elena and Tremmel suspect the camping owners. Felix infiltrates in order to catch the suspect.
First poisoned by a serpent's bite, then wholly cooked in a washing tunnel. That's how they find their latest victim. Felix could have solved the case quickly, but he suffers from a sudden memory loss.
With Tremmel still grieving from his breakup with Constanze, the team together with Felix has to solve a woman's murder who has turned up tied to the blades of a wind turbine.
