Spending her holidays on the Swiss/Italian border, Margareta (Lina Romay) meets charming Sandra Mauro (Monica Swinn) and her husband. She agrees to stay in their house for the rest of her vacation, unaware that they are going to use her for smuggling diamonds over the border. There they get a little 'deeper' into knowing each other, but one night she awakens to strange noises and finds the couple brutally murdered in their living room. Margareta, deeply traumatized and unable to speak, is taken to Dr. Antonio's asylum.