Macbeth boasts that his castle can withstand a siege indefinitely but its disturbed by the cry of women. Hearing that Lady Macbeth is dead, he reflects on the pointlessness of life. A messenger brings news that Birnam wood appears to be moving and Macbeth begins to wonder whether the Witches might have deceived him. Weary of life, he determines to fight to the last. Malcolm gives orders about the attack.
“As I did stand my watch upon the hill, I looked toward Birnam, and anon, methought the wood began to move.” – Messenger