In 1900, Stepha, the vivacious 30 year old daughter of a wealthy couple, agrees to marry her cousin Paul, who has accumulated large debts as an Austrian army officer. Paul refuses to work or to consummate the marriage, and then his health steadily declines.

Jealous of her vapidly "good" sister's popularity, poisonous Viktoria doses pretty Klara's tea with a slow-acting fatal substance. As the latter grows hysterically weak, the former finds success increasingly compromised by guilt, blackmail, and the pesky need to kill others lest she be exposed.