I have heard That guilty creatures, sitting at a play, Have by the very cunning of the scene Been struck so to the soul that presently They have proclaim’d their malefactions; For murder, though it have no tongue, will speak With most miraculous organ. I’ll have these players Play something like the murder of my father Before mine uncle: I’ll observe his looks; I’ll tent him to the quick: if he but blench, I know my course. The spirit that I have seen May be a devil: and the devil hath power To assume a pleasing shape; yea, and perhaps Out of my weakness and my melancholy, As he is very potent with such spirits, Abuses me to damn me: I’ll have grounds More relative than this. The play’s the thing Wherein I’ll catch the conscience of the king.