Besides being very pretty, intelligent and combative, Yoko Tsuno is an electronics engineer who always remains faithful to her values: loyalty, friendship and respect for life. In this volume, a megalomaniac businessman has stolen the artificial typhoon created by Yoko's father and intends to use it as military weapon. Hundreds of lives are in danger. Yoko and her teacher, Aoki, eventually manage to neutralise the typhoon - but Aoki has to sacrifice himself in the process.