With his murder investigations, Pirmin bites the dust everywhere - including with Bax. He wants to save his colleague Julie from dating scammers. He is also confronted with a tragedy that threatens to throw him off track. And the bankrupt Fricker sends workers into a deadly trap.

Pirmin goes to Bax in Bern and bursts into his therapy group. With Bax's support, Pirmin wants to prove that the notary did not commit suicide, but was killed. But Bax doesn't want to know anything about it. Disappointed, Pirmin returns to Valais and learns from Dr. Schmidhalter that the notary was really poisoned. In addition, a mysterious key turned up during the autopsy - yes, another key. Pirmin tries to convince the French Tschugger that there is something fishy about the case, but is only laughed at and rejected. Later, the two dubious French Flics stop him and intimidate him. Where should Pirmin get help? Federal police officer Annette is also on the trail of something again.

Bax is faced with a tough problem himself: Julie, a colleague from the therapy group, has found an admirer on the Internet with a tragic family history - the admirer's son is suffering from a terrible illness and needs money immediately for expensive emergency surgery. When Julie shows Bax the dating photo, this Romeo strangely looks extremely familiar. Bax and Stöffu – another therapy colleague – want to hunt down the fraudsters with a sophisticated operation. But Julie, blinded by love, threatens to sabotage the action. A completely unexpected tragedy threatens to throw Bax off course.

Construction contractor Fricker is facing bankruptcy and can no longer pay wages. The workers storm the villa. To get out of trouble, Fricker shows his workers where a treasure of gold is hidden.

Bax and Co. come across Smetterling in the Pfynwald, where he has gone into hiding and is active as a mafia hunter. When the mafia shows up, there is a big showdown in the Pfynwald. What the Tschuggers don't know: The criminals have Valmira in their power.

June reveals to Bax and Pirmin where Butterfly is hiding from the mafia. As a paranoid prepper, he lives in seclusion in the Pfynwald, but can defend himself against all external threats. They ask Butterfly to assist them in their investigation. But he refuses. Bax has to show a new side of himself to convince Butterfly.

Valmira is dissatisfied with Romi and Claudi's music management - so she is unable to progress with her career. She demands her money back. But with this she is biting the stones with both of them. That's why she asks construction lion Fricker for support. But he has his own worries: He has the mafia in the house who are looking for Butterfly. They want to take him to task for the death of family members. They kidnap Valmira and take her to the Pfynwald. There is a big showdown with Butterfly, Bax & Co.

A race against time begins: Bax and his colleagues have received unmistakable clues as to how they can solve the mystery surrounding the mysterious key. The tracks lead them to a cemetery, where they start a macabre operation. But what the Tschuggers don't know is that two dubious French Flics are hot on their heels. And they are at least as dangerous as the mafia.