In 1973, the 20-year-old Svante has a heart condition that the doctors cannot fix. When he has a breakdown on a subway platform, a strange train suddenly appears. He steps into the subway car filled with wonder, without knowing that the destination is the future. In the future he meets Elsa and together they must solve Svante's problems and figure out how to live together when they are from two different eras.
Murder investigator Evert Bäckström is convinced that crimes have been committed when a women's cranium is found on an island in the archipelago. But his investigation is countered by the police chief and when the woman's identity is clarified, the entire investigation is turned upside down.
When Johan and his colleagues are watching Seth and his gang member Jack, they stumble on a larger case than they expected. Seth is selling arms to terrorists, but without Jack's knowledge, in a car where Johan's old colleague Pernilla mysterious appears. While Johan begin researching what Pernilla and SÄPO is doing, Jack suspects that everything is not right with Seth and that he's working with the police.
