This scene is in Macbeths castle and begins with a soliloquie of Macbeth thinking over things. He is thinking about how if he is to become king, he must kill Duncan, and he may as well get it over with and kill him straight away. However, because Macbeth is a “honorable man” (we now know he is not…) he starts to convince himself not to, because Duncan has so much trust in him and his death would be very sad for many people. He also realises that killing a king would have huge consequences if he was caught, but eventually decides to go ahead and kill Duncan, only because of his big ambitions, “ I have no spur
To prick the sides of my intent, but only
Vaulting ambition, which o’erleaps itself
And falls on the other. “
Just then Lady Macbeth enters and asks where he has been. Macbeth rapidly jumps to conclusions (probably feeling follish or guilty) and says “We will proceed no further in this business:”, deciding NOT to kill king Duncan. This enrages Lady Macbeth, who yells and insults Macbeth, who replies by saying he is a man and has things under control. This does not help. She gets even angrier and eventually convinces him to kill Duncan by saying he has no dedication (she, however, would kill her own child while breast feeding if he told her to) and is a coward. Then she gives him a plan- she will get the guards drunk so they can enter and kill the king, then they will blame the guards and smear their daggers with blood. Macbeth praises lady Macbeth for convincing him and prepears to pretend he is innocent when he says “False face must hide what the false heart doth know.“
