Kalle Blomkvist
Anders Bengtsson
Eva-Lotta Lisander
Rasmus Rasmusson
Policeman Björk
Nicke Karlsson
Peters
Prof. Rasmusson
Kalle's father
Kalle's mother
Mia Lisander
Stenberg
Blom
Eva-Lotta's father
Berggren
Chief Constable Öman
State police
Kalle Blomkvist and his friends intervene when a professor and his little son Rasmus are kidnapped.