Macbeth
The shortest of the tragedies and by some distance the fastest. A man hears a prophecy in Act 1 and has committed the murder by Act 2; everything after is consequence, accelerating. Its compression is the whole design — there is no subplot to slow it, and almost no comic relief beyond one drunk porter whose scene arrives at exactly the worst possible moment, which is the point of it.
What the sisters actually say
They tell Macbeth he will be Thane of Cawdor and king hereafter. The first is already true when they say it, unknown to him. The second is a statement with no instructions attached. Nothing in their language proposes murder; Macbeth supplies that himself, within thirty lines, and is appalled at himself for doing so.
The later prophecies work the same way. No man of woman born shall harm him; he is safe until a wood moves. Both are true and both are traps, not because they are lies but because he hears the reassuring reading and discards the other. The play is precise about this: every catastrophic step is a decision, and the supernatural does no more than tell the truth in a shape that invites misreading.
The name is worth knowing. Weird here is the old wyrd, fate — they are the Fates, not eccentrics — and the folio calls them the Weyward or Weird Sisters, never witches
in the dialogue proper. Four centuries of pointed hats have obscured a much colder idea.
Lady Macbeth
She is given the most direct will in the play and then systematically removed from it. In the first two acts she is the strategist: she reads the letter, decides, steadies him, manages the aftermath, takes the daggers back to the chamber when he cannot. By the middle of the play he has stopped telling her his plans — the murder of Banquo is arranged without her — and her last appearance is sleepwalking, washing hands that are clean, speaking in prose.
That arc is the play's cruellest structural joke: the two characters swap. He begins hesitant and ends past feeling; she begins implacable and ends undone by exactly the imagination she told him to suppress. Her death is reported in half a line and he responds with the most desolate speech in the canon, which is either grief or the total absence of it, and productions have gone both ways for centuries.
The imagery
Three image systems run continuously and are worth tracking on a first reading. Clothing: honours are borrowed robes, ill-fitting garments, a giant's robe on a dwarfish thief. Sleep: murdered, denied, counterfeited, the innocent sleep that knits up the ravelled sleeve of care. Blood: which starts as evidence, becomes a stain, and ends as an ocean he is too far into to turn back.
Almost nothing in the play is decorative. The imagery is doing structural work, and reading the text with any one of the three threads in mind produces a coherent second play underneath the first.
The Scottish play
The theatrical superstition about naming it is genuine, old and universally observed in the profession, with the usual elaborate remedies for anyone who breaks it. The historical Macbeth ruled Scotland for around seventeen years in the eleventh century and by the standards of the period was not especially bloody; the play's version comes to Shakespeare through the chronicle tradition, heavily shaped, and should not be read as history. Background on the chronicle sources is set out in the Life and Times section of the Internet Shakespeare Editions.
The text also carries a well-known editorial problem: parts of the Hecate material, including songs, are generally thought to be later additions by another hand. It survives in performance because it is theatrically effective, not because anyone is confident Shakespeare wrote it. The Folger edition flags the disputed passages.
Drawing them
The cauldron is the tempting image and it is the weakest — it makes the sisters into stage business. The stronger subjects are private and domestic: two people in a corridor with a candle, discussing what they have just done in short broken lines; a woman standing at a door listening; a man looking at his own hands as though they belonged to somebody else. The play's horror is almost entirely interior, and the drawings that work are the ones that trust that.