Act 1

In Act I, Scene VII, Lady Macbeth enters, and Macbeth tells her that he "will proceed no further in this business" (31). But Lady Macbeth taunts him for his fears and ambivalence, telling him he will only be a man when he carries out the murder. She states that she herself would go so far as to take her own nursing baby and dash its brains if necessary. She counsels him to "screw [his] courage to the sticking place" and details the way they will murder the king (60). They will wait until he falls asleep, she says, and thereafter intoxicate his bodyguards with drink. This will allow them to murder Duncan and lay the blame on the two drunken bodyguards. Macbeth is astonished by her cruelty but resigns to follow through with her plans.

1) Duncan may not go to sleep.

2) The bodyguards might refuse the drink..... or they might wake up (or stir) in the midst of the attack on Duncan.

3) Someone might walk into Duncan's chambers.

4) Macbeth might be seen.