Producer Olle Nordemar had a small company, Artfilm, and he knew Rolf Husberg who directed Master Detective Blomkvist. Together they contacted Astrid Lindgren and were allowed to make the next film, Master Detective and Rasmus. Astrid's collaboration with Olle Nordemar then continued for decades.Master detective Kalle Blomkvist and his friends witness a kidnapping of a little boy and try to intervene. The role of little Rasmus was played by Eskil Dalenius, who had made a success of the radio series about Master Detective Blomkvist. Astrid Lindgren was asked to quickly write several scripts, all with Eskil Dalenius in the role of a boy named Rasmus (see Tramp and Rasmus and Rasmus, Pontus and Toker).