The opening scene allows us to see that there will be an inversion of values and something "unholy" will be taking place in what we are about to witness. The Three Witches enter and give the prophecy that the civil war will end that day and that at sunset they will meet Macbeth. The Witches are summoned to leave, but they do not leave without stating that what is normally “fair” will be “foul,” and what is “foul” will be “fair.” The fact that they are engaged in conversation that seems entirely normal to them, but abnormal to us helps to create a mood of mystery. Additionally, the overcast skies in the opening scene help to create a theory of correspondence where weather will reflect emotions and instability, furthering preparing the reader for something unbecoming which will unfold. Finally, the witches' inversion of value where "fair is foul and foul is fair" tells us that we are entering a domain where our traditional conceptions of right and wrong, justice and equity will leave us and entering a world without moral order or structure. The absence of this holy and spiritual framework represents a warning to evil and inhumane actions.