In Macbeth, one of the overarching themes has to do with honoring one's moral values. Throughout the play, the motifs of blood, hallucinations, and prophecy show the dangers of allowing ambition to overtake a person's better judgement and moral code. From the beginning, Macbeth challenges fate by trying to ensure that the witches' prophecy comes true. On a few occasions, he even tries to get fate on his side: for example, when he plots to have Banquo murdered, he asks that fate change its course to be on his side and make him the champion in the end. This goes against the moral code of the time--a time during which people believed more in the power of fate over that of free will. Further, Macbeth shuns his own moral code when he kills Duncan and later Banquo and Macduff's family. After the murders, Macbeth hallucinates images that reveal his guilt, and Lady Macbeth imagines that she sees blood on her hands, another symbol for the guilt that she feels over her part in the murders. So, the motifs of blood, hallucinations, and prophecy are directly linked to the theme of the play.