When Macbeth comes home and tells her that Duncan is coming to stay with them she thinks that this is the time to make the prophecy come true. She tells Macbeth to "look like th’innocent flower, but be the serpent undr’t". This means that he must look normal and keep his evil inside him. She starts to make a plan on how they can kill Duncan.
Lady Macbeths character becomes more cruel and callous and she has to take a more dominant role with Macbeth to make sure that he carries out the plan to kill Duncan.
When Duncan arrives at Macbeth’s castle the first thing that he says is how nice it is. He trusts Macbeth and Lady Macbeth. He does not realise that Lady Macbeth is taking him by the hand to his killer.
Lady Macbeth has to make her husband think that he must kill Duncan so that he can become king. She tells him that it was his idea and taunts him that he is a coward, which is cruel because Macbeth is very proud of how brave and courageous he is. She uses emotional blackmail to encourage him to change his mind and to kill the king. She also tells him that he must not be in love with her if he will not do it. Macbeth is really cross about this as they have a very good relationship. Before Macbeth kills Duncan, he thinks a lot about it. He has "no spur to prick the sides of [his] intent, but only Vaulting ambition". This is the mistake that kills him in the end. When Macbeth tells Lady Macbeth that he is not going to do it she accuses him of not being a man by saying, "I have given suck and know how tender ‘tis to love the babe that milks me: I would, while it was smiling in my face have plucked my nipple from his boneless gums and dashed his brains out, had I so sworn as you have done to this. This means that she would not have gone back on her word if she was the one promising to do it. Lady Macbeth succeeds in convincing Macbeth to carry on with the plan and Macbeth says he is only worried that he might fail. Macbeth also refers to children by telling Lady Macbeth to bring forth only male children because she is too evil to bring forth girls, which makes you wonder if Macbeth and Lady Macbeth can have children
Lady Macbeth gets drunk while she is waiting for Macbeth to come back from Duncan's room. She has drugged the bodygaurds, but is still worried about the murder. Macbeth comes back to the room and tells her that Duncan is dead. Macbeth is feeling guilty and cannot say the word "Amen". Lady Macbeth orders him to give her the daggers, and after awhile he gives them to her so that the blood can be smeared on the guards.
After Duncan has been killed Lady Macbeth starts to feel lonely and scared. Macbeth has changed and he is not nice to her. He is so busy running the country that she is left on her own and she gives into the guilt which preys on her mind until she starts to go mad. She starts to sleep walk and the memory of Duncans death is always with her and will not go away.
