In the fourth episode of The Chestnut Man: Hide and Seek Season 2, Mark embarks on a relentless pursuit of Peter. Sandra questions Lena, Ditte's girlfriend, who surmises that the couple must be at their wedding tavern in Praesto. At the tavern, Ditte attempts to soothe Peter's nerves by pretending to make coffee. Suddenly, the lights dim, Peter vanishes, and the countdown rhyme echoes through the air. As Ditte reaches for her phone to play it, she receives a text that reads "found you." The police arrive to find the bodies, revealing that Peter has brutally killed Ditte with an axe and then fatally shot himself.
Aksel breaks the news of Naia's murder to Le, causing her to flee in despair. For moral support, Signe drives Marie to her meeting with Anders. Bo has been dismissed for his dalliance with Silje, but he has an alibi for the night Emma went missing. Sympathetic to his plight, Anders places Marie on leave. However, Signe interrupts to reveal that the news claims Peter is Emma's killer. The axe found at the crime scene matches the murder weapon used in Zara's death. Despite this evidence, Mark still doesn't believe that Peter is the stalker.
The task force learns that the stalker has targeted Naia. Esra would have removed her from the case if she knew, and Mark feels a sense of guilt. Esra urges him to take some time off and speak with a counselor, but he declines. As a compromise, Esra tasks him with returning Naia's belongings. When he arrives, Aksel, who has never approved of Mark, advises him to give Le space.
Marie seeks answers but Esra remains tight-lipped. The ever-supportive Signe drives Marie home, and she is grateful for the ride. However, when Marie arrives home, she finds Michael and Thor in a state of distress. In her haste to keep up with the latest developments, Marie had forgotten about Molly's dentist appointment and practice. She tries to explain the situation, but Michael is uninterested in hearing it. Thor and Molly are upset that she isn't there for them, but Marie doesn't know how to let go of her responsibilities.
Le approaches Mark and breaks down in tears. She wants to live with him, but he doesn't think he can provide the family she deserves. He takes her back to Aksel's and gives her Jon's canary as a token of his affection.
Alone, Mark perseveres in his investigation. He successfully convinces the coroner that the stalker may have initially killed Peter with the axe and subsequently used the rifle to fabricate a suicide scenario. The agency's CCTV footage captures the tires of a passing car as Naia, in her dying moments, attempts to pursue the couple. Bloodstains are discovered near the tavern's front door, reinforcing Mark's theory of a third party involvement. This theory is further validated when a nearby workshop's CCTV footage captures a car parked on the night of the couple's deaths. Mark enlists Sandra to trace the vehicle, despite her concerns about his exhaustion.
The Holsts decide to clear out Emma's belongings as they try to move past her loss. They reflect nostalgically on her cap that reads "stay gold girl," prompting laughter and heartfelt moments. Naia delves into the 1992 case, and the relevant tapes arrive. Mark shares his third-person theory with Esra, but she dismisses it, citing that Emma and Zara's DNA was found on the axe and that Peter was Emma's soccer team's assistant coach. Mark remains unconvinced and insists Peter is not the stalker, causing a scene until Esra escorts him home. On his way out, he secures the 1992 tapes.
Esra breaks the news to Marie that Peter is Emma's killer, prompting tears and a comforting embrace among the family members, all while an unseen observer watches on.
Back at the hotel, Mark scrutinizes the interrogation tapes of the 1992 perpetrator, Staal. Staal begins to speak of cuckoos ejecting other birds' eggs, adding a sinister layer to the already grim narrative.
