She plans it to every detail, leaving only the act itself to Macbeth. She instructs Macbeth to be deceitful, "[to] look like the innocent flower, // But be the serpent under't." .
As the gentle Duncan arrives to stay at Macbeths castle, the opportunity to dispose of him arises. Ironically, Duncan speaks of the apparent pleasantness of the place that shall serve as his last bed as, "This castle hath a pleasant seat." Before the murder, Macbeth begins to show his internal influences, attempting to hide any suspicions, "Away, and mock the time with fairest show; // False face must hide what the false heart doth know." As Macbeth approaches the moment of the dreadful deed, he sees a floating dagger in the direction of Duncan. Perhaps a manifestation of his mind, appearing to be real, Macbeth says ".or art thou but // A dagger of the mind, a false creation." .
Immediately following the murder, Macbeth is overcome with feelings of quilt, which are soothed by the words of Lady Macbeth. To hide their guilt, they place the bloodied daggers upon servants of the king, "For it must seem their guilt." Malcolm, son and heir to the throne, flees upon his fathers death, fearing to looks guilty, and doesn't wish to consort with anyone else, fearing they would be the murderer, "To show unfelt sorrow is an office // Which the false men does easy." Thus, in lack of any rightful heir, Macbeth assumes the duty of the throne. .
Macbeth begins to become more and more deceitful and underhanded as the play progresses, and in fear of Banquo line, decides on his own accord to have Banquo murdered, this time without his wife's urging and without remorse, saying "Banquo, thy soul's flight, // If it find heaven, must find it out tonight." Macbeth does this in an attempt to establish his own line on the throne, in stead of Banquo's, which was prophesied my the Weird Sisters. After Banquo's murder, Macbeth begins to fall apart.
