Marie-Chantal Froidevaux des Chatenets travels by train to her cousin's home in order to spend a winter holiday, when a stranger - apparently a fugitive from somewhere abroad - entrusts her with transporting a jewel in the shape of the head of a blue tiger with ruby eyes over the Swiss border. Unknown to her, this phony jewel contains within it a virus that is powerful enough to destroy all mankind. Doctor Kha is just one of many spies from different nations that are trying to get their hands on either the jewel or Marie-Chantal...it would give any nation tremendous control over all of the others. Marie-Chantal, a snobbish socialite, evades all attacks on her by sheer female cunning and shows tigerish qualities in dealing with both her male and female foes.