The investigator Arthur gets one step closer to uncovering the secret behind the mysterious substances found in the baby carriage. Train driver Edith and Kurt, the cameraman, are also getting to know each other better.

The train is approaching Bamberg, causing the passengers to speak frankly with one another. Gerd is standing in the corridor and Marlis is sitting in the compartment. What will he decide?

The pressure on the train passengers increases as the train gets closer to East Berlin. Political views and personal desires and fears differ greatly, making it very difficult for couples to reach a decision.

In the inter-zone train to East Berlin, people listen to the distressing radio reports. At the same time, we get insight into the lives of other people on this August 13, 1961 - the day when the Berlin Wall is erected and begins to separate its residents from the rest of the world.

Antonia confesses everything to the principal, and Martin Schulze can return to school. But Antonia's behavior has consequences...

August 13, 1961: A fateful message reaches the train bound for East Berlin: The construction of the Wall has begun. The passengers now have three and a half hours to decide—home or freedom?

With Sophie's help, the young detectives are able to record a conversation between Antonia and Sophie that proves Martin Schulze's innocence.

Femi is very worried about being taken away from his foster family. The young detectives stay on the case to expose Antonia's story for the lie that it is.

Kira's interference blows the whole thing wide open, leading to Mr. Schulze's suspension.

While Antonia increases the pressure on Mr. Schulze, the young detectives look for ways to get to her phone.

Our young detectives find out that Antonia is blackmailing Tayo's father.

The Peppercorns are back again!
In the first part of this new episode, a student is trying to blackmail Mr. Schulze in order to get a better grade. Nele is temporarily in the same class as her brother and Tayo, who is also Mr. Schulze's foster son.

The environment concerns everyone—including these roommates! How can people be convinced to recycle and sustainably change their behavior as consumers? The four discuss what could be done.

Yara and her landlord are talking about climate change. Yara is appalled by how some people are so indifferent to the issue.

The final part of the episode sees the criminals apprehended and the Pfefferkörner delighted by a surprise parting gift from Kim.