In Shakespeare's Macbeth, Act Three, scene four, Macbeth has previously arranged for Banquo's murder, showing no conscience in planning the death of a fellow-warrior, hero, and best friend. In this scene, one of the murderers comes to report the results of the "task" Macbeth had charged them with in Act Three, scene one.
When Macbeth comments on the blood on his face, the murderer reports that it is Banquo's, and that Banquo is dead. Macbeth has no remorse for what he had done; in fact, the only thing he cares about is that Banquo's son Fleance has also been killed. He is distraught when he discovers that Fleance has escaped, believing that his survival will be as much a threat to Macbeth as Banquo's would have been, and he admits that his fears come upon him again; however, he seeks assurance again that Banquo is truly dead. Macbeth asks:
Is [Banquo] dispatch'd?
My lord, his throat is cut; that I did for him.
Thou art the best o’ the cut-throats! Yet he's good
That did the like for Fleance. If thou didst it,
Thou art the nonpareil. (20)
Most royal sir,
Fleance is 'scaped.
Then comes my fit again: I had else been perfect,
Whole as the marble, founded as the rock,
As broad and general as the casing air: (25)
But now I am cabin'd, cribb'd, confined, bound in
To saucy doubts and fears.—But Banquo's safe?
Ay, my good lord. Safe in a ditch he bides,
With twenty trenched gashes on his head...(III.iv.16-29)
Macbeth has acted without conscience, not only in arranging his friend's death, but in accepting it so casually. He displays no regret. When he reports these recent events to his wife, he expresses no guilt; he only observes that Fleance is like a young snake ("worm") that is not dangerous now, but could be one day:
There the grown serpent lies; the worm that's fled
Hath nature that in time will venom breed,
No teeth for the present. (III.iv.32-34)