Kissing before Customers, that's Gretchen and Sarah's motto. And both are flirting with the enenmy. Literally. Clemens, who with his business partner is after the same assignment as them, is the center of their attention. When it comes to his intentions, though...

Tom does not have it easy. At the student theater, his friend Jan and his beloved Annelie play the leading roles; the inconspicuous Tom, on the other hand, makes the prop. When he realizes that he must finally take his life, and especially love, into his own hands, he turns to his janitor, Mr Müller. What Tom does not know: Müller was once a psychologist of the Stasi! In the so-called "Romeo" program, he prepared male agents to address women in Germany and make them available as a source.

Thomas Borchert is already looking forward to his goddaughter Jenny, who is completing a practical semester in Albania. At the airport, as part of the baggage check, half a kilo of hashish is seized from her, which Jenny claims she did not know anything about. Borchert and Dominique Kuster want to find out who could have put the hash on her. They also have to solve the murder of an entrepreneur who was involved in crooked business.

Lawyer Dominique Kuster can feel a professional success for herself when her underage client Stefan, the oldest of three foster children, receives mitigating circumstances. After the court hearing, however, she found out that the foster father Christian Hunziker had a fatal accident in a car. An autopsy reveals that it was murder. Someone has swapped the dead man's insulin for ineffective water. Christian's wife Martina comes under suspicion.

Borchert wants to toast three years of successful cooperation with his superior Dominique Kuster and her father, Reto Zanger. The evening is canceled because Reto Zanger is called to Geneva at short notice for a mandate. His daughter is therefore supposed to represent him at a court hearing in Zurich. The trial takes a dramatic turn when inmate Alexander Böni takes those involved as hostages.

When Borchert receives an anonymous message that a certain Franz Brosi is innocent, law firm boss Dominique can hardly believe it. After all, Brosi was her first client as a public defender a few years ago and had actually confessed. The two are investigating the case.

The lawyers Borchert and Kuster are investigating a case involving a young student who has come under the crosshairs of a terrorist group.

Anton Schneider says goodbye to his wife Luise in tears and dies. Schneider was seriously ill with multiple sclerosis and was diagnosed by neurologist Dr. Hoffer medically treated. Luise Schneider reports the doctor and accuses him of incorrect treatment of her husband, which ultimately led to his death. The mandate against Dr. Hoffer takes over Dominique Kuster, who entrusts her employee Thomas Borchert with the investigation.

Kindergarten teacher Hannah lovingly creates a calendar of activities for the coming year to get her relationship with her boyfriend Simon back on track. Through a mishap, however, the calendar falls into the hands of misanthropic Jonathan, a wealthy publishing heir who sets out to find the author with growing curiosity. Miraculously, the paths of the two cross from then on, for the time being without knowing of their connection through the calendar.