The opening scene of Macbeth sets the narrative and theme for the entire drama. It has the three witches determining their reunion on a battlefield to manipulate the returning war hero, Macbeth. They reveal their plan to cause much confusion and chaos in his life by clouding the ability to differentiate between goo and evil.

The setting itself is dark with thundering clouds and strong winds. It creates an atmosphere of dread, suspicion and misfortune that is continuous through the following acts.

The idiom suggested by fair and foul and a layer of fog between them introduces the audiences to the central idea of the drama which is the dark outcome of lust for political power and selfish ambition.