After the murder of King Duncan, Lady Macbeth is alarmed to see her husband losing his grip on reality.
Macbeth has stabbed Duncan, King of Scots, as he lay in his bed, hoping to give a little assistance to a witch’s prophesy that he would one day be King. Both Macbeth and his wife, who is the driving force behind the plot, are understandably jittery; but it soon becomes clear to the ever-competent Lady Macbeth that her husband is losing his grip.