Macbeth is an amazing play write by the one and only Shakespeare. The Thane of Glamis was crowned the Thane of Cawdor, which is pretty much the next step in line to be crowned King. That causes bad thoughts and feelings, now that Lady Macbeth knows he is next in line almost to King. She feels Macbeth should kill the King to be crowned King, and when Macbeth tries to resist she makes him feel like he is immaculate. Then things don't go as planned and it goes downhill from there.