The recurring enemy, whose projects Buck Danny and his friends manage to thwart at the last minute, is, in this series, a woman who always calls herself “Lady X”, Jane Hamilton in civil status. She appears for the first time, not physically but only in the conversations of the American pilots, in the album Menace au Nord, before she gives her name to the following album. According to Jean-Michel Charlier it is inspired by the authentic character of Hanna Reitsch, test pilot and German aviation ace.
She is an American aviator famous for her performances and her aeronautical records, coupled with a high-flying spy. She accumulates all the clichés of the espionage genre: beautiful, mysterious and unscrupulous: her venality leads her to betray her country shamelessly. It therefore offers its services and information to the highest bidders. She worked for the Axis during World War II and was even the mistress of a Japanese admiral, a position modestly expressed as “I have been very friends with …”.