Once again we meet the sworn members of the White Rose (Kalle, Eva-Lotta, Anders) and the Red Rose (Sixten, Benke, Jonte). In the idyllic little town of Lillköping, the war between the Red Rose and the White Rose continues. For the moment the Reds are gaining - that is, the Great Mumbo, (”The Stormumrik”), is in their possession. One night, when the Whites are trying to recapture the Great Mumbo, they witness a professor and his 5-year old son Rasmus being kidnapped by strangers. The professor has invented an impenetrable bullet-proof metal and he has the formula hidden in his house. Eva-Lotta gets into the kidnappers’ car and, leaving a trail of clues, leads Kalle and Anders to the kidnappers’ headquarters, a lonely house on an island. The gang boss tries to force the professor to disclose where the formulas are hidden. Rasmus knows where the documents are and, not realising the threatening situation, reveals the hiding place.Luckily The Master Detective Kalle Blomkvist is near by. Will he manage to get to the hiding place first and secure the pages? Once again we meet the sworn members of the White Rose (Kalle, Eva-Lotta, Anders) and the Red Rose (Sixten, Benke, Jonte). In the idyllic little town of Lillköping, the war between the Red Rose and the White Rose continues. For the moment the Reds are gaining - that is, the Great Mumbo, (”The Stormumrik”), is in their possession. One night, when the Whites are trying to recapture the Great Mumbo, they witness a professor and his 5-year old son Rasmus being kidnapped by strangers. The professor has invented an impenetrable bullet-proof metal and he has the formula hidden in his house. Eva-Lotta gets into the kidnappers’ car and, leaving a trail of clues, leads Kalle and Anders to the kidnappers’ headquarters, a lonely house on an island. The gang boss tries to force the professor to disclose where the formulas are hidden. Rasmus knows where the documents are and, not realising the threatening situation, reveals the hiding place.Luckily The Master Detective Kalle Blomkvist is near by. Will he manage to get to the hiding place first and secure the pages?