The melodrama has been seen, by directors as disparate as Douglas Sirk and Orson Welles, as "the last form of tragedy in a bourgeois world". Whether or not we choose to accept such a claim, melodrama has for centuries provided theatre audiences with access to a world, where vice and virtue seem to be clearly defined. The serious artist may blur that distinction, whereas an artist who chooses to work in this genre has little interest in the complexities of morality. Whatever the case may be, the fierce clash of good and evil rarely fails to please.

Juraj Herz's film is a melodrama which has been linked with those Hollywood psychological dramas of the '40s, which seemed to be able to find an infinite number of variations upon a formula. Here, our attention is focused upon the struggle for power between two sisters: Victoria, the bad one, who is envious of Clara, the good one, who inherited their parents' wealth. So Victoria sets out to poison her. The poison, however, is supposed to take four weeks to work, and this creates the suspense essential to melodrama. During this period, we see the death of Morgiana, the sisters' Siamese cat, which accidentally drinks some of the poison. In addition, we are offered some insight into the frustrations of the villainous Victoria, and the plot thickens. Meanwhile, Morgiana's spirit remains ever-present.