An engineer and his 5-year old son Rasmus are kidnapped by a group who wants to get their hands on the engineer's latest invention. Three kids become witnesses to the kidnapping and decide to follow the kidnappers to an island and attempt to make a rescue.
as Anders
as Eva-Lotta
as Kalle Blomkvist
as Rasmus
as Nicke
as Peters
as Blom
as Poliskonstapel Björk
as Professorn
as Sixten
as Jonte
as Benke