At the gruesome crime scene, the investigators find clues regarding the murder's motive, including something very disturbing about the victim.

Lona tries to learn more about the victim and how the body was discovered, and Elling learns that his wife couldn't have met with her intern that day, as according to a colleague, he was sick.

Susanne Elling comes home unsuspectingly and is puzzled by the guests in her living room. She must have forgotten something...
In the nursing home, Mr. Dreyer is wheeled out onto the terrace. After his caregiver has gone back inside, the murderer strikes again.

During the garden party, Elling's daughter asks her father if something has changed in her parents' relationship. A little later, Elling is called to a new crime scene and, together with Lona, he makes initial assumptions about the perpetrator and motive.

In the first part of the season "Posthum" ("Posthumously"), we get a brief recap of what has happened so far. Then we follow Lona, Jasper, and Elling to the forensic institute, where the pathologist shares the results of his examination with the team, and the investigators speculate about the course of events.

Elling, Lona, and Jasper continue discussing the investigation results. Lona has discovered something that justifies a trip to Marnow, where Beck regularly stayed at a specific campsite once a year. Lona and Elling set off, leaving Jasper to conduct further investigations on site.

Elling seems to notice that something is going on between Lona and Sören Jasper. When Elling visits the forensic pathologist, he learns something there that changes everything.

This crime series is not for the faint of heart. The new episode of The Dead of Marnow begins with a summary of previous events and ends with a wild car chase.

Lona and Elling drive to Santovaal, the company where Dreyer worked for years. From Dr. Fichte, they learn that Dreyer was a very distinguished employee to whom Santovaal owes a great deal.

Sören Jasper goes to the fish stand at the Marnow campsite to do a bit of snooping around. He tries to strike up a conversation with the regulars, who knew Beck but mainly give him a hard time.

Peters manages to find out the current state of the investigation from Lona and Elling, but he doesn't reveal any information himself. Elling is suspicious, so he calls the Schwerin Criminal Investigation Police Office to check if everything is above board.

Elling gets a bug from Forensics to listen in on his wife. When she leaves the house again in the evening for an exclusive interview, Elling follows her. Will his suspicions turn out to be correct?

Susanne and Benedikt are lying in bed together, and Elling is listening in on their conversation. Lona returns to the camper after a long swim in the lake and wonders where Jasper is. Finally, the phone finally rings, but it's not Jasper on the other end of the line...

Elling is eavesdropping on his wife and Benedikt, heartbroken, when Lona calls with urgent news: He needs to go to Marnow immediately—Jasper’s been kidnapped.

Lona and Elling arrive at the old church and look around. They meet Pastor Rilling, but he cannot provide them with any information about Jasper's whereabouts. Meanwhile, the police question the campsite residents, but they don't have any useful clues either.