In Act I, Banquo and Macbeth went to talk to three witches. The witches were very ugly, which confused Banquo. The witches told Macbeth and Banquo that they each had three prophesies. Banquo didn't quite believe what he was being told and neither did Macbeth. Macbeth knew the Thane of Cowdor was still alive so he didnt know how he was going to be king.
Your father is a traitor!!
In Act II, Macbeth knew that the only way he would be king was to kill king Duncan. Lady Macbeth ordered Macbeth to kill the king. Macbeth headed towards Duncan's room with the daggers. He killed the guards and Duncan while he was sleeping. After killing king Duncan he went back to Lady Macbeth but returned with the bloody daggers.
In this act, three murderers were sent to kill Banquo and Fleance. They succeeded in killing Banquo however, Fleance got away. When the killers informed Macbeth of the escape, he was shocked a nervous. He was scared that the people would not make him King if they knew that he had sent people to kill his enemies. Now they have to think of what to do without getting caught. Macbeth is then left alone so he can think of what to do while acting normal so nobody will suspect anything.
In Act IV, Lady Macduff and her son have a discussion about macduff. Lady Macduff calls Macduff a traitor for leaving without saying anything. They dont know that Macduff left England to find help so they can kill Macbeth. Macduff's son is positive that his father is not a traitor. Later, man that Macbeth sent, kills Macduff's son trying to find Macduff.
No! You're wrong!!
In this last Act, Macbeth and Macduff start sword fighting. Macduff wants to kill Macbeth but Macbeth doesnt give up. Macduff doesnt yet know of the killing of his son. Eventually Macduff kills Macbeth and finds out how Macbeth killed his son. He finds out his son was killed from the front, meaning he wasnt running away which makes Macduff proud of his son.