After serving six years for killing her husband, former public prosecutor Karin Lossow is granted an early release. Against her parole officer's advice, she returns to Usedom and her old house, now known as the eponymous "murderer house".

A supermarket manageress from Ahlbeck on the island of Usedom is found dead in the neighboring Polish resort of Swinemünde. Inspector Julia Thiel and her Polish colleague Marek investigate. The dead woman was planning to meet one of her employees to discuss a mysterious property swap. The case is a challenge for Julia Thiel, because her mother of all people is a "legal adviser" to the main suspect. To cap it all, her adolescent daughter is proving difficult, having found out she's having an affair with her Polish colleague.

Sophie works in a cafe and becomes friends with Jadwiga, the girls are used to cycling together after work; one day, Jadwiga is kidnapped, and Julia, in rehabilitation after suffering an accident, sets out to find the truth about the case.

A homeless is injured in a fire on a yacht docked, Julia discovers that earlier the ship was involved in an accident where a couple was murdered but their son survived, then she wonders if he's returned to the island to avenge his parents.

Participants in an illegal car race are surprised by police and try to flee, during the escape a young man is run over and dies. Former prosecutor is driving with the son of a friend when, suddenly, a car comes directly in front of her.

Stefan hasn't heard from his wife for days and he's starting to get worried, with his mother-in-law Karin they decide to leave it to look for her in Stettin, where they learn that Julia is investigating a private assignment.

Julia's death upsets the family, Stefan doesn't accept it and Karin tries to be distracted working. Meanwhile, the owner of a restaurant is the victim of a fail robbery but the victim and the perpetrator finally end up losing their lives.

Karin is asked by Brendal to help a friend of his who was convicted of shooting her lover. Karin doesn't believe the woman's story of self-defense, so both the German and Polish police try to work out what happened.

Danish rescue divers and a dead woman puzzle the police. Ellen Norgaard suspects the body is her mother.

The architect Sascha Hoerne was crushed and then drowned. His death shakes the Sievers family. The father-in-law had big plans with him and his future wife is pregnant by him. The brother-in-law is under suspicion.

16-year-olds who were drugged until unconscious in a holiday bungalow, one of them dead in the sauna - this is how the new tourism season begins in a Usedom imperial bath. It was Karin Lossow's great-nephew Ben's party that escalated there. His father Rainer arrives, Karin's nephew, who has not been seen for a long time and who works for the Munich police station. He promptly interferes in Ellen Norgaard's investigation, because his son is suspect: Did Ben kill his buddy? Both were deeply in love with Felice, who was molested that night - not just by a man, it turns out. Nobody can remember, not even Felice. However, there are witnesses: seniors from the neighboring bungalow. Soon one of them is seriously injured in the dunes, Karin finds him just in time.

Erika Brunner, the mother of Dr. Dirk Brunner. The prosecutor learns that the head of nursing Kerstin Matthies had apparently mistreated his mother. Which hits Brunner all the harder when he was in a relationship with Mrs. Matthies until recently. A little later, the nursing manager disappears - a violent crime? Brunner comes under suspicion. The prosecutor, who was stalked by journalists and bloggers, is looking for support from his opponent Karin Lossow. She hides it - in the area of the bison enclosure where she works. Brunner sees himself as a victim of a plot and suspects that the perpetrator is someone he has put behind bars. Together with the ex-prosecutor and Ellen Norgaard, Brunner is investigating his old cases. The three come across a murder case in which he does not play a notable role.

After her divorce from the local politician Victor Braydon, Simone Eggebrecht found support in working with the disabled and in friendship with the paralyzed Wiebke Siehl. Simone's plan to build a handicapped hotel in a prime location is torpedoed by anonymous acts of sabotage. She hires Patrick Horn as a guard. When the young man disappears, Simone blames her ex-husband and his party colleague Enno Littmann and pulls Commissioner Ellen Norgaard and her colleague Rainer Witt into their war of the roses. Karin, who starts a romance with Inspector Gadocha, wants to stay out of the way and finally put her own interests first. But it is precisely her own struggle for happiness in life that allows Karin to find the true motive and the tragic perpetrator.

Ellen Norgaard's first day back at work after maternity leave ends in disaster: Her son Jesper is kidnapped from daycare.

It burns on Usedom: Karin Lossow's thatched roof house is on fire. At the last moment she can escape the house with Ellen Norgaard's help. Karin has suffered smoke inhalation and is immediately taken to the hospital. In the clinic, she befriends former nurse Saskia Bernard, who was hit by a car and seriously injured. Saskia was on her way to physical therapy when the car caught her. The young woman recovers quickly, but she cannot remember the accident. The car and driver have disappeared without a trace. Who was going to kill Saskia? And why? Saskia's life revolves around her husband Kolja, who has been in a vegetative state for years and whom she looks after around the clock. A motive is not recognizable. Ellen and her colleague Rainer Witt have a tough nut to crack with the investigation and Karin can't help but follow her own tips.

Ulf, Eva and Renate, all in their seventies, party lively during a camping trip in Poland. The next day, Ulf, confused and taken away, is found by hunters at the edge of the forest. He thinks he killed someone but can't remember anything. He is hospitalized helpless and desperate and police commissioner Lucjan Gadocha is notified. At a border control, Holm Brendel and Dorit Martens stop Eva's camper, which catches fire and explodes. Holm and Dorit suspect that the three are smuggling gasoline to supplement the tight budget. You have the car checked. Renate's body is found in the forest. At the same time, Karin Lossow takes care of Ellen Noorgard's son, while Ellen overcomes herself and visits her mother Patrizia in prison. Karin has not been doing well since her house burned down. She misses living with Ellen - and the relationship with Gadocha. Although she is temporarily staying with her nephew Rainer Witt, she doesn't really feel welcome in the Witt house.

The prominent TV presenter Sandra Berger is dead. The gardening entrepreneur Britta Hausmann finds the TV lady dead in her Usedom holiday home. Chief Inspector Ellen Norgaard is shocked when she meets the dead man's husband, also well-known TV presenter Jonas Gomez, at the scene of the crime. The two are linked by the well-kept secret of a passionate affair. Karin Lossow senses that Ellen is doing badly. The inspector pours out her heart to her friend. Nobody in the police station suspects that Ellen was meeting Jonas Gomez at the time of the crime. It would mean the safe end of her career in the police and the probable career end for her lover, who has no alibi for the time of the crime and is also being blackmailed. The group of suspects also includes the employees of the gardening company, who were staying at the couple's holiday home before Berger's death, as well as the Greifswald art dealer Schwenkers, who was also seen there.

School secretary Annett Ludwig is jogging by the sea. Under a steep cliff she discovers a dead teenager: Theo Jacobsen, a student at her school. The 17-year-old was considered an inconspicuous outsider. Karin Lossow knows Theo from business school, where she teaches a course on legal issues as part of a project week. By chance, she had observed a bullying attack on the best in the class, Theo, and offered the boy her help. Rainer Witt and his colleagues Holm Brendel and Dorit Martens examine Theo's laptop. It turns out he ran a thriving trade in test questions, which he sold to his classmates, making thousands of dollars in profit. To do this, the alleged model student used access to the server of the board of directors - only school secretary Ludwig knew the password. Theo was deeply in love with their daughter Paula. But Paula raves about Karol Wilcek, who has nothing to do with the pubescent classmate. Theo apparently wanted to prove to Paula that she loves the wrong person.

Police Superintendent Holm Brendel follows in the footsteps of the prominent Swedish crime writer Arvid Johanssons in Ystad. Ex-prosecutor Karin Lossow accompanies Holm on the private trip. On the ferry back to Usedom, she meets Dana Driest, who was born in Poland. She has a noticeable hematoma on her cheek. Has she been a victim of domestic violence? The next day, Karin saw Dana's husband Jochen drive off the ferry at the wheel of his SUV - without his wife. Meanwhile, Dr. Brunner to new tasks in Estonia. His successor on Usedom will be public prosecutor Katharina Stozek, the partner of Chief Inspector Rainer Witt. Karen makes a decision. She wants to get back on board the ferry where she last saw Dana. As she buys her ticket, Brunner calls, his fingers tingling three days before his move. He wants to support Karin in her research and ensure that his former colleague moves on the ground of legitimacy. But Brunner's plan fails.

A young woman is chased through the Usedom Forest and falls into a trap, with her pursuer close on her heels. The scene turns out to be survival training that the loner Ivo Klose offers to 18-year-old Fabienne Leppin. At the same time, Karin Lossow discovers dead puppies in the forest while walking with her dog Lucky. She informs Holm Brendel, but the police are currently at major construction sites: Jana Leppin, Fabienne's mother, is missing. A large pool of blood in her car indicates a violent crime. Suspicion quickly falls on Ivo Klose, who has already served a long prison sentence for manslaughter and who Jana Leppin was afraid of. Jana Leppin was an employee of a nursing service. While Inspector Rainer Witt questions the employees, clients and the manager Elena Herzog, the discovery of the dead puppies gives Karin Lossow no peace.

While Karin Lossow is inspecting the construction site of her future home on Usedom, eight refugees from Afghanistan and Syria are waiting at the Belarusian-Polish border to be transported further by a group of smugglers. Among them are Ahmad Bashmani and his little daughter Amira. The refugees are brought into a van that sets off towards the west. At the wheel was the completely tired Grzegorz Kuchar. Although little Amira is suffering from severe stomach pain, the smuggler doesn't want to stop the car to get help. And so the girl is dead when the transporter arrives in Usedom the next morning. On the way to the construction site, young Lara Scherer meets the traumatized Ahmad with his lifeless daughter in his arms. She alerts Inspector Rainer Witt, who begins the investigation together with his team and prosecutor Katharina Stozek. While Rainer asks around the refugees and talks to Amira's loving mother Nadia Bashmani, Karin Lossow approaches the carpenter Jörn Scherer.