‘That’s something the patient must do himself.’

Macbeth stared at the doctor for a moment then he made a dismissive gesture. ‘Throw medicine to the dogs! I don’t need it.’

Seyton came in, followed by two servants carrying Macbeth’s armour.

‘Come, put it on. Where’s my commander’s baton?’ He pointed at the doctor. ‘Doctor, the thanes are fleeing from me.’ He turned back to Seyton. ‘Come on, hurry. If, Doctor, you could analyse a sample of my country’s water and diagnose her disease, then bring it back to perfect health, I would applaud you to the rafters and the echo of that would applaud again

He snarled at the servants: they had positioned one of the pieces incorrectly. ‘Pull it off: go on, pull it off. Doctor, what rhubarb or senna or other purgative drug would purge these English.’

He walked away from the servants, who had only half finished dressing him. ‘Bring it with you.’ He strode to the door and out, towards the battlements. ‘I won’t be afraid of death and destruction till Birnam forest comes to Dunsinane.’

The doctor whistled softly to himself. If he were far away from Dunsinane, no money on earth would bring him back