Macbeth is a faithful servant of the king of Scotland who is euphoric because he has managed to win a major battle, so that the king himself has promoted him. When everything ends he receives three witches, who tell him that in time he will be king, but that he will not leave offspring.
When he tells his wife what the witches have told him, they decide to speed up the prediction. They invite the king to his house and kill him while they sleep, saying that it has been the guard who has committed the regicide.
That makes Macbet king, as they predicted. The problem is that the guilt begins to destroy it inside, which makes the glorious warrior becomes a bad king, always with fear.
Macbet and his wife constantly seek conspiracies and see them where there are none, because guilt makes them fear that both will end up as the king they murdered.