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.
Dr. Rössler, Felix's doctor, is involved in a murder case during a paintball game which appears to be more serious than it seems.
Eckart Steffens, captain of the dart team "The Wild Bumblebees," dies from an anaphylactic shock due to a wasp toxin.
When Einstein attempts to deposit his day-night solar cell in a bank safe deposit box, a hostage situation ensues. Now Einstein must not only retrieve his prototype, but also ensure the safe return of the hostages from the danger zone.
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.
The dismembered body of a drug dealer turns up. The case bears similarities to a murder that took place 18 years ago. Einstein becomes a suspect. Unfortunately, Constanze has erased his memory in an experiment.
