Random Thoughts.....What Are You Thinking?

"In here is a tragedy---
art thou player or audience?
Be as it may, the end doth remain:
all go on only toward death.

The first words at thy left hand:
a false lunacy, a madly dancing man.
Hearing unhearable words, drawn
to a beloved's grave---and there,
mayhap, true madness at last.

As did this one, playing at death,
find true death at the last.
Killing a nameless lover, she
pierced a heart rent by sorrow.

Doth lie invite truth?
Doth verity but wear the
mask of falsehood?
Ah, thou pitiful, thou
miserable ones!

Still amidst lies, though the end cometh not,
wherefore yearn for death?
Wilt thou attend to thy beloved?
Truth and lies, life and death:
a game of turning white to black
and black to white.

Is not a silence brimming with
love more precious than flattery?
A peaceful slumber preferred to
a throne besmirched with blood?

One vengeful man
spilled blood for two;
Two youths shed tears for three;
Three witches disappeared thusly;
And only the four keys remain.

Ah, but verily...
In here is a tragedy---
art thou player or audience?
There is nothing which cannot
become a puppet of fate or an
onlooker, peering into the cage."

The above memo, which describes the puzzle, is located by the locked door. Read it carefully and then examine all the anthology books in the inventory. Both the books and the memo must be considered to solve this puzzle.

The first and final verses are just an introduction and conclusion to the poem, so just pretend they don't exist.

The 1st verse is Hamlet, which is Anthology 4.
"A false lunacy" describes how Hamlet feigned to be crazy. The "unhearable words" are those of Hamlet's deceased father, the ghost. Hamlet's "beloved" is Ophelia, and at her funeral, a fight occurred between Hamlet and Laertes.
The 2nd verse is Romeo and Juliet, which is Anthology 1.
"Playing at death" refers to how Juliet pretended to be dead by using the sleeping potion. The "nameless lover" is Romeo, since the Capulet family had never known of his love. Juliet is partially responsible for Romeo's death, and she suicides due to her grief.
The 3rd verse is Othello, which is Anthology 5.
It speaks of truths and lies being reversed. Othello thought Desdemona was guilty of adultery when in reality, she was innocent. The characters in the story believed Iago's lies were actually truth.
The 4th verse is King Lear, which is Anthology 2.
It refers to Lear's daughter Cordelia and how she chooses to remain silent when asked how much she loves her father, in an act of vanity on Lear's part, unlike her sisters who offer only false flattery.
The 5th verse is Macbeth, which is Anthology 3.
It refers to King Duncan being murdered by Macbeth in his slumber, as well as Lady Macbeth's flattery of Macbeth. Macbeth takes Duncan's throne.
From left to right, with all the books in proper order, the code is 41523. However, the words "only four keys remain" indicate an extra number is still present. There's still more of the memo left to read.

"One vengeful man (Hamlet) spilled blood for two", and Hamlet is 4, so replace the 4 with an 8 (double it). The code becomes 81523.
"Two youths (Romeo and Juliet) shed tears for three", and Romeo and Juliet is 1, so replace the 1 with a 3 (triple it). The code becomes 83523.
"Three witches (from Macbeth) disappeared", and Macbeth is 3, so get rid of the last 3.
The final answer is 8352.