Macbeth Act V, Scene i Summary

Back in Scotland, at Macbeth's castle in Dunsinane, a doctor waits with one of Lady Macbeth's gentlewomen. The two keep watch for Lady Macbeth's sleepwalking, which the gentlewoman reported began once Macbeth left to prepare the house for battle. The gentlewoman refuses to tell the doctor what else she's seen or heard during Lady Macbeth's nightly strolls.
Lady Macbeth shows up walking (make that sleepwalking). She carries a candle, and the gentlewoman notes she insists on always having a light about her. They proceed to watch Lady Macbeth ramble through a tortured speech, at once trying to clean her hands of an imaginary spot (that would be blood, don't you think?) and chiding her invisible husband to be brave at what must be done. All the hand wringing and her question, "Who would have thought the old man to have so much blood in him?" leave little doubt as to what vexes the lady. (This is also where we get the famous line, "Out, damned spot!")
In her sleep, she further assures her invisible husband that Banquo, being now dead, cannot trouble them. She goes back and forth in her speech between strength and self-pity – "what's done cannot be undone." The doctor diagnoses Lady Macbeth with a heavy heart and says he can do nothing to help her.
Then the doctor says he's heard a lot of nasty little rumors that are floating around and says it sounds like Lady Macbeth probably needs help from the divine (a priest or God), not a doctor.