Besides being pretty, intelligent, and courageous, Yoko Tsuno is an electronics engineer. This specialization draws her and friends Pol and Vic into adventures across the border between fantasy and science fiction. Yoko crosses the travels through time and space, but no matter where her exploits take her, she 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, struck down by a mysterious disease that leaves her powerless. Yoko Tsuno also realizes that a strange vampire, dressed all in black, is shadowing her.