In Act III of Macbeth, what is the price that Macbeth and Lady Macbeth pay for their murderous actions after the slaying of Duncan?
Clearly, the courting of the phantasmagorical in which the Macbeths experience a complex succession of things seen or imagined causes paranoia and hallucinations within them. Much like the verse from Robert Frost, for the Macbeths "way leads to way" and it is a path of insomnia, hallucination, and madness.
Because the Macbeths first consider their acts as "fair" when they are really "foul," they invite confusion between the realm of the imagination and that of reality. After the murder of Duncan when Macbeth is ridden with appropriate guilt, with great dramatic irony, Lady Macbeth superciliously declares to her husband that
A little water clears us of this deed:
How easy is it then! (2.2)
And, so, Macbeth tries to sweep away his guilt with his "vaulting ambition" and places more faith in the power of the supernatural. Having thus courted the supernatural, Macbeth invites this realm into his life. He tells Lady Macbeth that they must make their
...faces vizards to our hearts,
Disguising what they are. (3.2)
But, as Sir Walter Scott wrote, there is a tangled web that is wrought with deception, and the Macbeths themselves become confused about what is real and what is not. When suppressed guilt overcomes her, Lady Macbeth becomes delusional and imagines blood on the stairs of the castle until her guilt and madness lead to her death. Likewise, as the drama progresses, Macbeth, in his meglomania, cannot distinguish the real from the imagined and perceives Birnam Wood moving as in the witches' equivocation. And, when he faces Macduff, who informs him that he was "untimely ripped" from his mother's womb, Macbeth finally realizes his self-deception. Nevertheless, the warrior Macbeth vows to fight to the end: "But, bearlike, I must fight the course." He, like Lady Macbeth, pays the ultimate price for his courting of the preternatural world and his irrational "vaulting ambition."