With the possible exception of King Lear, no character in any of Shakespeare's plays undergoes such a radical devolution as that which transforms Lady Macbeth from a nearly superhuman character in the first act of Macbeth into a sleep-walking zombie at the start of Act V. When we first see Lady Macbeth on stage, she is plainly in command of her faculties and, in fact, she has deliberately intensifher capacity to realize her royal ambitions for power. …
