Having drugged the guards of Duncan's chamber, Lady Macbeth now meets her husband in the lower courtyard as he emerges from the king's room itself. Macbeth's conscience is clearly disturbed by what he has done, and once more his wife criticizes his lack of firmness. The success of their plot is also in jeopardy because Macbeth has brought the daggers with him. Lady Macbeth returns to the scene of the murder in order to place the daggers and to smear the king's sleeping servants with blood, a deed that presents her with none of the horror that now affects Macbeth. As the scene closes, we hear, with the Macbeths, a loud and persistent knocking at the door.
