The life of grief therapist Vera turns upside down when Isak joins the group and recalls memories from his disappearance in childhood. Vera realises that the story is strikingly similar to her childhood, when her brother went missing 20 years ago.

Isak vanishes without a trace; Vera returns to her childhood home in Skåne, where she informs Ebbe and her brother about her suspicions that Billy could be alive; Vera realises she lied to the police about what happened when Billy went missing.

Vera decides to go to the site where Billy was allegedly held captive; Vera unexpectedly meets Isak again and they together look for answers to who he actually is; Mattias tries to dismiss the theory that Isak is Billy with the help of a DNA test.

In 1984, Billy goes missing and police chief Månsson leaves no resources to track him down. However, Reftinge's strongman, Harald, has his own idea of how to locate Billy.

When Vera helps Isak remember his childhood, she discovers an alternate explanation for what might have happened to Billy; Mattias decides to assist Harald in tracing Isak's identity.

Vera realises that she never really understood what was happening when she was a kid. Together, she and Mattias try to solve the mystery surrounding Billy's disappearance.