A woman leaves her husband and children without saying goodbye. While she struggles to build a new life, her family is left completely uncertain of her fate. The radical nature of her departure appears to be an opportunity as well as a trauma. The film is structured in three episodes, each showing a different perspective of the subject. The first one accompanies the woman in Vienna and Bratislava, creating a new life for herself. Although her past remains untold, she seems driven by it. The second episode portrays the life of her abandoned husband and their children, two years after her disappearance. Their days are still dominated by her mysterious leaving. The final episode returns to the last evening of the family.
Styx depicts the transformation of a strong woman torn from her contented world during a sailing trip. When she becomes the only person to come to the aid of a group of refugees shipwrecked on the high seas, she is shown the limits of her importance and of the empathy of her cultural milieu. She is left slipping impotently from one nightmare to the next, and by the end she is forced to recognize that there is no way to counter the cruelties of real life. Only chance can save her.