CAITHNESS                Well, march we on,

To give obedience where ’tis truly owed.

Meet we the medicine of the sickly weal,

And with him pour we in our country’s purge

Each drop of us.

LENNOX                     Or so much as it needs

To dew the sovereign flower, and drown the weeds.

Make we our march towards Birnam.

Exeunt marching        (5.2.25-31)

And so the thanes are off to rendezvous with Malcolm, Macduff, and the English troops, to give obedience where ’tis truly owed, to Malcolm, the rightful heir to the Scottish throne (and, perhaps, loyalty and service to Macduff, too, in avenging the particular wrong that has been done to him). Malcolm will be the medicine of the sickly weal, both physician and himself the healing drug for the diseased state of the land and its people, wounded, violated, polluted by Macbeth and his crimes. As has been established so clearly in the England scene, the rightful king is both a healer and a cure, and Malcolm’s claim to the throne is being strengthened by the language used about him by the thanes. United with Malcolm, they will pour in our country’s purge each drop of us. (The purge is a literal one: emetics and enemas were central to early modern medical practice, cleansing and rebalancing the body.) The thanes and their men will also be like medicine, drop by drop, but they’re prepared, too, to sacrifice their blood, drop by drop, give their lives, their all, in order to cleanse Scotland and heal it from the wrongs that have been done. Lennox concurs, neatly widening the conceit of the body politic, an organism which must be purified and rebalanced, to encompass the natural world too. They’ll give as much (blood, implicitly) as is needed to dew the sovereign flower, nurture, nourish and beautify Malcolm as the true king (dew as jewels, as crown, even; dew often a sign of heavenly blessing and divine favour, like manna), and drown the weeds, those choking, unwelcome interlopers in the garden of the state. Make we our march towards Birnam. Birnam again. Off to the woods, in a neat literalisation of these horticultural conceits. Exeunt marching, an orderly, purposeful cohort in contrast to Macbeth’s increasingly chaotic existence, about to be encountered once again.