Act 4, Scene 1
The witches circle a cauldron, mixing in a variety of grotesque ingredients while chanting "double, double toil and trouble; / Fire burn, and cauldron bubble" (10-11). Hecate appears, they sing all together, and Hecate leaves. Macbeth then enters, demanding answers to his pressing questions about the future. The witches complete their magic spell and summon forth a series of apparitions. The first is an armed head that warns Macbeth to beware the Thane of Fife (Macduff). The second apparition is a bloody child, who tells him that "none of woman born / Shall harm Macbeth" (96-97). This news bolsters Macbeth spirits. The third apparition is a crowned child with a tree in its hand, who says that "Macbeth shall never vanquished be until / Great Birnam Wood to high Dunsinane Hill / Shall come against him" (107-09). This cheers Macbeth even more, since he knows that nothing can move a forest. Macbeth proceeds to ask his last question: will Banquo's children ever rule Scotland?
The cauldron sinks and a strange sound is heard. The witches now show Macbeth a procession of kings, the eighth of whom holds a mirror in his hand, followed by Banquo. As Banquo points at this line of kings, Macbeth realizes that they are indeed his family line. After the witches dance and disappear, Lennox enters with the news that Macduff has fled to England. Macbeth resolves that he will henceforth act immediately on his ambitions: the first step will be to seize Fife and kill Macduff's wife and children.
Act 4, Scene 2
At Fife, Ross visits Lady Macduff, who is frightened for her own safety now that her husband has fled. He reassures her by telling her that her husband did only what was right and necessary. After he leaves, Lady Macduff engages her son in a conversation about his missing father. The little boy demonstrates wisdom well beyond his years. A messenger interrupts them with a warning to flee the house immediately. But before Lady Macduff can escape, murderers attack the house and kill everyone including Lady Macduff and her son.
Act 4, Scene 3
Macduff arrives at the English court and meets with Malcolm. Malcolm, remembering his father's misplaced trust in Macbeth, decides to test Macduff: he confesses that he is a greedy, lustful, and sinful man who makes Macbeth look like an angel in comparison. Macduff despairs and says that he will leave Scotland forever if this is the case, since there seems to be no man fit to rule it. Upon hearing this, Malcolm is convinced of Macduff's goodness and reveals that he was merely testing him; he has none of these faults to which he has just confessed. In fact, he claims, the first lie he has ever told was this false confession to Macduff. He then announces that Siward has assembled an army of ten thousand men and is prepared to march on Scotland.
A messenger appears and tells the men that the king of England is approaching, attended by a crowd of sick and despairing people who wish the king to cure them. The king, according to Malcolm, has a gift for healing people simply by laying his hands on them.
Ross arrives from Scotland and reports that the country is in a shambles. When Macduff asks how his wife and children are faring, Ross first responds that they are “well at peace” (180). When pressed further, he relates the story of their death. Macduff is stunned speechless and Malcolm urges him to cure his grief by exacting revenge on Macbeth. Macduff is overcome with guilt and sorrow from the murders that occurred while he was absent. Again Malcolm urges him to put his grief to good use and seek revenge. All three men leave to prepare for battle.
