The opening scene of Macbeth not only captures our attention but it also seems to strike the key-note of the play.
1) The scene captures our attention because it is laid in "a desert place", barren and eerie-looking, away from human habitation;
2) The three witches appear in adverse weather, amidst thunder and lightning, the adversity of weather presumably born of their incantation, an adversity which is more supernaturally conjured up, rather than natural;
3) The "weird sisters" look alien and intent on some evil mission, and they speak of a future meeting with Macbeth on a "heath";
4) The witches converse in a strangely stylized manner and in an enigmatic, paradoxical language;
5) The most captivating aspect of the scene is, however, the anarchical formula that they chant in chorus: "fair is foul, and foul is fair", a formula that strikes the key-note to the whole play.