Macbeth sends assassins to murder Banquo and his son, but his son, Fleance, escapes. Later that evening, Macbeth is haunted by the ghost of Banquo. Macbeth goes to see the Witches again.

Lady Macbeth:A foolish thought, to say a sorry sight. Macbeth:There's one did laugh in's sleep, and one cried, "Murder!" that they did wake each other: I stood and heard them: but they did say ...