The story takes place in the complex and vast space of the Paris Metro. Fred escapes to the metro after stealing the briefcase from Helena's husband, where he meets a group of long-term metro dwellers including the roller-skating drummer known as "Nameless." Fred approaches Helena for the money to redeem the documents, while both the henchmen of Helena's husband and the police are pursuing him. As Helena searches for Fred to retrieve the documents, she gradually falls in love with him, becoming increasingly disloyal to her own class and living environment. Fred, who suffered a throat injury as a child and is unable to sing, has always dreamed of forming a band.