Kalle Blomkvist and his friends intervene when a professor and his little son Rasmus are kidnapped.
A member of "Sjöbjörnarna" (a group of executives), asks the newspaper editor Dick Mattson to find Brita Ljungdahl, the former wife of another of the members. The first clue he tries is to ask a certain Maria Vaern, who knows Brita.
Karl Oskar Bohm looks back at his life, his estranged daughter Augusta and his wife Sofia.
