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In scene 3 of Act 1, the witches give Macebth and Banquo their predictions, they greet Macbeth as Thane of Cawdor and King of Scotland. After finding out that Macbeth is indeed given the title of Thane of Cawdor, the readers find out his tragic flaw, his ambition and lust for power. It is this ambition that drives him to commit murders and ultimately leads to his downfall.