LADY              You must leave this.

MACBETH      O, full of scorpions is my mind, dear wife.

Thou know’st that Banquo and his Fleance lives.

LADY              But in them nature’s copy’s not eterne.

MACBEH        There’s comfort yet. They are assailable.

Then be thou jocund. Ere the bat hath flown

His cloistered flight, ere to black Hecate’s summons

The shard-borne beetle with his drowsy hums

Hath rung night’s yawning peal, there shall be done

A deed of dreadful note.                   (3.2.36-45)

You must leave this: you must both let this go, stop obsessing about it and stop acting like this, full stop. That makes no impression at all: full of scorpions is my mind, dear wife. Brilliant: the humdrum, perfunctory dear wife, and the baroque horror of full of scorpions is my mind. A crawling, spring-loaded glitter, poisonous and piercing; so many stings in so many tails. The well-ordered mind is like a bee-hive, in early modern thought, harmonious, productive, and controlled; these spiky horrors are the antithesis of that. No wonder Macbeth can’t sleep… Thou know’st that Banquo and his Fleance lives—that’s the obsession, the stone in the shoe, the lump in the pillow. That’s what’s quite literally, if anachronistically, bugging Macbeth. (Or at least that’s what he thinks is the cause of his unease, his dis-ease.) But in them nature’s copy’s not eterne: so what, in effect. That doesn’t mean that their posterity will last for ever, this whole father to a line of kings business. Macbeth’s more literal, perhaps: you have a point indeed, dear wife; they’re not immortal, they can’t live for ever. There’s comfort yet. They are assailable; they can be dealt with, disposed of. Then be thou jocund (it’s such a jarring word in the context): cheer up, love, it might never happen! I’m on it, trust me.

And now one of the play’s most chilling, vivid yet creepily imprecise flights of fancy. Ere the bat hath flown his cloistered flight, before the bat has gone for his nightly turn around the building (the bat, here, the antithesis of those nice martlets whom Duncan admired as having built their lovely healthy nests on the ramparts). And ere to black Hecate’s summons the shard-borne beetle with his drowsy hums hath rung night’s yawning peal, before the beetle, which is shard-born because it is born in dung, or shard-borne, because its wings are scaly, they look like something shattered and sharp, the beetle which makes a hum as it flies, a soporific sound that might herald sleep, make you yawn, like a bell signalling that it’s time for bed (but bells in the play have signalled that it’s time for murder, not for sleep), the beetle which is summoned by black Hecate, queen of the witches. Before all of those things, that collage of ominous gloomy blackness, bat, beetle, Hecate, scorpions too, all slightly off in its word choices and grammar (how is flight cloistered? How does a peal yawn? or a bell? or night itself? it’s the trick, which is employed elsewhere in the play, of describing something in a way which seems to promise visual precision but actually frustrates it)—something terrible, notorious, evil will be done. Basically, before nightfall, there shall be done a deed of dreadful note.