Lady Macbeth is delighted at the idea of him becoming King and started to plan the killing when she found out that the king was coming to stay in their castle that night. When planning the murder Lady Macbeth is in control. This is a turning point for Lady Macbeth as we see a different side to her and she determines she will assist him becoming king whatever the cost, she exults and invokes demonic spirits to harden her own resolve and to destroy any weakness of pity. Her ambition for power leads her into an unnatural, phantasmagoric realm of witchcraft, insomnia and madness:.
"That tend on mortal thoughts, unsex me here,.
And fill me, from the crown to the toe, top-full.
Of direst cruelty! Make thick my blood -.
(Act 1 scene 5 lines 40-43).
When King Duncan arrives at Macbeth's castle Macbeth starts to debate about killing Duncan because he cannot dismiss the fact that Duncan has been such a good king but Lady Macbeth persuades him by accusing him of being a coward and questioning his manly hood:.
"When you durst do it, then you were a man;.
And, to be more than what you were, you would.
Be so much more the man.".
(Act 1 scene 7 lines 49-51) .
When Macbeth decides to go through with the murder Lady Macbeth finishes of the plans and Macbeth leaves to go do the deed. Banquo has a feeling that something is wrong. Macbeth and Banquo meet and discuss what the witches had said; after Banquo retires Macbeth who is alone imagines he sees a blood-stained dagger leading him to Duncan's chamber. He talks to the dagger and then the bell rings and he goes through with the murder. Although Lady Macbeth doesn't commit the murder she panics and is excited at the same time but still stays in control. The reason in which Lady Macbeth cannot commit the murder is that the king asleep made her think of her father.