Thou canst not say I did it; never shake
Thy gory locks at me.

– William Shakespeare

Macbeth, Act 3, Scene 4. A horrified and unnerved Macbeth speaks to the ghost of Banquo that he sees sitting in his seat at the coronation banquet. The bloody apparition, visible to no one else, is a hallucination of Macbeth’s mind and a sign of his guilt and growing mental instability brought on by the murders of Duncan and Banquo. He tells the ghost that no one can say he murdered Banquo. He seems to deceive himself into believing that since he didn’t carry out the deed but only ordered it he is somehow innocent. The ghost’s “gory locks” is a reference to the twenty gashes to Banquo’s head delivered by his murderer. Macbeth is losing his mind at this point.