Katherine [Lester (a character in Lady Macbeth)] is no innocent. Her taste for evil is in her DNA, and her twists of the screw (literally and figuratively) tighten her resolve to control her destiny, no matter the consequence. In short order, we witness homicide, infanticide and even equicide.

There's a book of simple answers for that: The Codes. But you miss the context. It's not the meat, it's the motion. It's the way they reason.

They had spent their entire lives as prisoners in Siberia and they now appealed to the empress for their release. In a rare instance of unforgivingness Elizabeth refused to grant it.

Now, sir, what I have to communicate to you at present is, that at a late meeting of the stripping ladies, in which were present several eminent toasts and beauties, it was resolved for the future to lay the modesty-piece wholly aside