While cleaning out the headquarters to find items to bring to the flea market, Henri digs up an old Geiger counter. Meanwhile, Hannes’s ex-girlfriend Debbie shows up and starts behaving inappropriately, and Nina doesn’t understand why Max still won’t talk to her.

Just as Tarik realizes that Emma is hiding in the houseboat bathroom with the stolen hydrangeas, Max arrives and threatens to call the cops. Later, Max angrily approaches Marcello about Nina, but they don't share a common language, which results in a big misunderstanding.

Nina's grandpa arrives in good spirits. He’s even brought along Nina's cousin Marcello, who Max still thinks is Nina's ex-boyfriend! Meanwhile, Emma watches with interest as Jackie gets into a heated argument on the phone with her irresponsible brother, Marvin.

Emma discovers that hydrangeas are being cut off all over the neighborhood. Meanwhile, Jackie is heartbroken over being rejected by Nina’s dad. But that’s not her biggest problem right now…

Mr. Weber finally understands what it is that Lisa wants from him – and lays down the law. Meanwhile, Dennis — furious at having been snitched on — runs off with Lisa’s diary.

“Das Tagebuch” (“The Diary”) is a one-year short film project by Jan Herdin that was created as part of the Media Design program at Ostfalia University of Applied Sciences. Lisa is a lonely teenager growing up in a single-parent household. She finds it difficult to get along with her fellow classmates and has a crush on her teacher, Mr. Weber.

Matteo is caught by Mr. Sass with the stolen donation box, but claims that it was given to him by… a tiger? With Mr. Sass threatening to punish Matteo for a theft he may not have committed, the Peppercorns get to work on cracking the case.

Jan finds Milla’s mother just in time, and makes sure that she is taken to hospital. But where’s Milla? Emma and Nina go looking for her. With everything resolved, it’s time for the new team of Peppercorns to take the oath.

The Peppercorns finally find out why Nina was bullied at her old school. Meanwhile, Emma has a guilty conscience about having lied on Milla’s behalf — did she do the right thing? Jan heads over the next day to try to sort things out with Milla and her mother in person.

Nina gets in trouble with her father when he finds out she was the one who damaged the headmistress’s car. Meanwhile, Leila’s ex-partner Mark shows up to help Milla clean their filthy apartment.

Max confronts Dragan about the money Dragan is demanding from Max's grandmother... then finds himself in a bad situation.

When it becomes clear that his nephew Henri can't stay on his boat, Jan brings him to Emma's father, Hannes. Emma, however, is not happy to find that a guest has taken over her space in the attic – which also serves as the Peppercorn headquarters.

Nina's first day at school really isn't going so well, but she rejects Emma's help and doesn't tell her father what happened. Meanwhile, Emma's dad settles into their new apartment.

When a wallet goes missing in the girls' locker room, the girls immediately blame Nina, who is new at the school. Luckily, Emma and Max are already on the case.

In the first episode of Season 9 of Die Pfefferkörner, Emma is the only one of the pre-teen detectives left at school. Will she be able to keep the group going?