Phase 3 = Murder of Banquo → Banquet Scene
In order to secure the throne for his descendants, he must kill Banquo, the other army general, and Banquo’s son (Act 3, scene 1 – soliloquy “To be thus is nothing, but to be safely thus”) because the witches’ told Macbeth that Banquo’s descendants would have the throne after Macbeth. So Macbeth sets a trap and hires murderers to kill Banquo and his son, but Banquo’s son escapes. Shortly after Banquo is killed on his way to a banquet at Macbeth’s palace, Macbeth is haunted by Banquo’s ghost. In the middle of the banquet he sees the ghost of the murdered man and makes a scene in front of the Scottish lords. This outburst makes the lords suspicious although Lady Macbeth tries to play it off as just an illness that Macbeth has.
PHASE 3 – Protecting the Throne
The prophesy the Witches gave to Banquo now starts to haunt Macbeth “to be thus is nothing but to be safely thus – our fears in Banquo stick deep”.
This next section of the play effectively proceeds without her. She has to ask a servant to tell the King that she wants a word with him. She is full of despair because they have sacrificed their peace of mind and what they have gained (the throne) is meaningless because they cannot enjoy it “Nought’s had, all’s spent, Where our desire is got without content”. However she conceals her depression from her husband instead trying to lift his spirits “Things without all remedy should be without regard: what’s done is done”. He still confides honestly in her “o full of scorpions is my mind dear wife” but he no longer includes her in the decision-making process “be innocent of the knowledge dearest chuck, til thou applaud the deed” perhaps to protect her? Perhaps because he no longer feels he needs her input. However, she proves vital in the Banquet scene, doing her utmost to excuse his odd behaviour “Sit worthy friends: my lord is often thus and hath been from his youth… the fit is momentary” and then when it becomes clear that Macbeth cannot control himself sending them away before he ruins everything “Stand not upon your the order of your going but go at once”
Once you are King you can get away with anything. Macbeth has no trouble hiring murderers to kill Banquo & his son, convincing them that Banquo wronged them. He’s the King – whether they believe him or not they must obey. However, as ruler you need the support of your nobles. Macbeth cannot force Macduff to attend his coronation feast. He may be using underhanded tactics to spy on his subjects (“there’s not one of them but in his house I keep a servant fee’d”) but this is not likely to inspire loyalty, nor is his erratic behaviour at the feast going to do him any favours.
Macbeth very rapidly loses his moral compass – he freely admits that Banquo is a good man who does not deserve to die “in his royalty of nature reigns that which would be feared” but Macbeth didn’t allow this to stop him when it came to killing Duncan so he’s not going to let it stop him now. He really has transformed remarkably quickly into a selfish ruthless murderer. However, we do get a glimpse of his inner torture when he echoes his wife’s envy of Duncan who is now at peace “Better be with the dead, Whom we, to gain our peace, have sent to peace, Than on the torture of the mind to lie In restless ecstasy”. Once you start to feel jealous of those who are dead it’s just one short step to feeling suicidal yourself but Duncan is presumably in heaven whereas they are in hell, now and for all eternity! The banquet scene is proof of something Macbeth himself suspected before he ever killed Duncan – the idea of karma, that what goes around comes around “bloody instructions….return to plague the inventor”. Macbeth may be selfish and ruthless but he is also vulnerable, tortured, paranoid and terrified that he is losing his mind.