Lady Macbeth’s coldness and control is again shown when she begins to plot Duncan’s murder with Macbeth, and says he should 'look like the innocent flower but be the serpent under it´. Furthermore, she even goes to Duncan’s chamber to return the daggers displaying her cool control over such a serious matter.
We discover that as soon as she opens her husband’s letter she immediately begins to scheme and plot, showing her true evil and ambition. We can immediately become aware that she wants Macbeth to become King so that she can become the Queen of Scotland. She knows that Macbeth is too loyal and weak, and is not inherently evil, a quality that he would need to fulfil his already prominent ambition. For this reason, she takes upon herself the duty, to influence him into the prospect of murdering the king. The thought of becoming Queen pushes her and causes her to act outrageously. She calls on spirits, showing the presence of the supernatural, saying such things as ‘come, you spirits that tend on mortal thoughts, unsex me here…make think my blood…take my milk from gall’. She decides to pour all her spirits of evil into Macbeth and ultimately remove any fear that would hold him back from obtaining the crown. Macbeth however is on the other end of the scale in their relationship, and once, he plucked up the courage to tell her he does not want to continue with the murder. But she rallies, calling him a 'coward´, saying that if he could murder Duncan 'he were a man´ and by saying that his love is worth nothing if he refuses to go through with the plan. She says ‘screw your courage to the sticking-place’ to make him more evil and confident about his actions. This to Macbeth, a proud and mighty warrior is a deep insult, and he soon is convinced that he will carry out the murder. Lady Macbeth’s cold hearted side again shows, saying she would 'dash´ out the brains of her own child because she is so sure Macbeth should kill Duncan. We also see how Lady Macbeth’s influence has rubbed off on Macbeth, as he says 'False face must hide what the false heart doth know´, which is very similar to Lady Macbeth’s words of the 'innocent flower´ earlier.
In Act two, after murdering Duncan, Macbeth says 'This is a sorry sight´, but Lady Macbeth again shows her power over Macbeth. 'A foolish thing to say a sorry sight´. This shows how she is still callous, as she thinks it is 'foolish´ for a man to show remorse at a murder he committed. She orders him to not think 'so deeply´, saying that thinking about the deed 'will make us mad´ and 'unbend your noble strength´. Here we see a slightly weaker side to Lady Macbeth; she is herself feeling vulnerable to guilt, almost immediately after the murder. This is shown in 'will make us mad´. The 'us´ shows that she is no longer only concerned for Macbeth, but is worried about her own mental state too, fretting that she may go mad with guilt. But soon after, Lady Macbeth regains her control, and begins to once more organise affairs, such as telling Macbeth to get changed and to get rid of the blood stained clothes.
Although Lady Macbeth may be a strong cause for Macbeth’s reign of tyranny, she still greatly helps him through uncomfortable situations. She supports and helps him throughout his gradual decline. Because Macbeth is not completely certain of the success of the devious plan, he is greatly assisted by his wife. Lady Macbeth is worried that her husband will give their plan away through his facial expressions. Another example where she helps Macbeth is the incident after he has killed Duncan. As Macbeth is uneasy and mesmerised she takes the daggers back into Duncan’s chamber for him and helps him wash the blood off his hands. She is very useful in this situation as she helps pull him together psychologically. When Macbeth is speaking to Macduff directly after the murder he threatens to give the game away so much so that Lady Macbeth faints to draw attention to herself, ensuring that he doesn’t give too much away. Even in the banquet scene, Lady Macbeth plays a crucial role in support of her husband. The ghost of Banquo causes Macbeth much stress and places a huge amount of pressure on Lady Macbeth. Even though she cannot see the apparition herself she tries to cover up for him. She tries to get him out of this strange state of mind by once again questioning his manhood while at the same time giving the guests the excuse that Macbeth is not well. This shows that Lady Macbeth, though appears to be the cause of Macbeth’s downfall, only does it for her husband’s sake and ultimately wishes the best for him. Hence, as the play progresses, Macbeth and Lady Macbeth reverse roles, with Macbeth becoming an evil, heartless, greedy and merciless ruler, who is corrupt with over ambition and the obsession for kingship.
Also, it reflects that despite Lady Macbeth having a huge impact earlier on Macbeth, she is slowly ‘consumed’ by the guilt that she had a hand in killing Duncan, and eventually commits suicide. Macbeth on the other hand, relies on the three witches, and become ruthless in his way of keeping his kingship. He does not bother to tell his wife about his plans of hiring murderers to kill Banquo and Macduff’s family. In other words, Lady Macbeth cannot be completely blamed for Macbeth’s downfall as she does not play a strong part in the later stages of the play, and other sources such as the witches and as we see, the idea of becoming King obviously appealed to him for him to continue pursuing his ill ambition. Thus, Lady Macbeth can be seen as to have simply pushed Macbeth at the right time, as from the later parts in the play; Macbeth looses the need for his wife’s influence as he already has the instinct for evil and tyranny. Though Lady Macbeth plays the dominant role throughout the opening scenes asserting her ambition to gain hierarchic status for herself and her husband she loses importance as the play progresses. The relationship of Macbeth and Lady Macbeth clearly illustrates this change.
Macbeth and Lady Macbeth, who were very loving and close to each other at the start of the play, slowly drift apart as both of them take different approaches to the murder of Duncan. Macbeth becomes evil despite being remorseful, while Lady Macbeth becomes a helpless and guilty individual full of regret for what she has done. Eventually, she is unable to come to terms with the fact that her plan for status has failed, and she has lost her loving husband, and therefore kills herself, finally displaying her feminine and weak side as compared to Macbeth who fights till the end.