Besides being pretty, intelligent and courageous, Yoko Tsuno is an electronics engineer. This specialization draws her and friends Pol and Vic into adventures that cross the border between fantasy and science fiction. Yoko crosses the globe and travels through time and space; but no matter where her exploits take her, the young girl always remains faithful to herself, never forgetting values such as loyalty, friendship and respect for life. In this first volume, our heroine is called to the bedside of her friend Ingrid, who is struck down by a mysterious disease that leaves her powerless. Yoko Tsuno soon realizes that a strange vampire, dressed all in black, shadows her.