Joe tells Katja that her father actually committed suicide. The others back at the station are unable to find out any information about what happened to the weapon that night.

Frau Starke finds a diary that reveals that her husband had an alibi, proving he couldn't have murdered Katja's father.

Everyone weighs their options regarding the suspect's wife, who remains in custody, while Nicki's father proves himself to be a very difficult person to get along with.

Katja tells her mom that the police have found the murder weapon that killed Katja's father. Meanwhile, the wife of the top suspect is brought in for questioning.

While Katja, Ben, Henning, and Harry all look into the weapon that has surfaced, Lothar meets Nicki's father, who is a very difficult person.

Katja learns that the gun found on a teenager is the weapon used years ago to kill her father, who was also a cop.

Lothar finds out why Nicki is so stressed out about her upcoming exam. Meanwhile, Katja and Ben investigate when someone overhears a gunshot.

Everyone at the station speculates wildly when Dirk is mysteriously called away. Meanwhile, Katja observes the anniversary of her father's death.

After it is revealed that Frauke Claassen tried to frame Torben Witt, Eileen Claassen asserts her independence. Harry and Lothar get revenge on Dirk for his role in the confusion surrounding Harry's training program.

Harry and Henning have to apologize to Ina Grote and Onno Wulf. Meanwhile, the truth about what happened at Frauke Claassen's house is revealed.

It seems as if Torben has been caught red-handed and the evidence adds up against Onno. Can they convince the police of their innocence?

The police doubt the credibility of the evidence against Torben Witt and continue to watch over the Claassen residence. Meanwhile, Ina Grote helps with the arrest of Onno Wulf.

Frauke Claassen is certain that Torben set her car on fire, and the evidence also seems to point to him. Meanwhile, it becomes clear that Onno Wulf has been tampering with the card reader in Ina Grote's shop.

Harry, Henning, and Lothar find Onno Wulf's criminal record and warn Ina Grote. Harry finds out that Lothar is going to the training program, and confronts Dirk, who finds yet another excuse.

Henning and Harry visit Ina Grote's shop and meet a suspicious employee. Frauke Claassen requests that the security detail at her house be removed.