‘Usually,’ Mayhew agrees, staring up at icicles hanging from the roof. ‘Any lord of quality wants a physician, doesn’t he? But only really to fix him up. They’re expensive, you see? No one wants to waste his balms on a dying billman, does he? Be like ministering to a cow, or a dog. Mind you, William Hastings is a good man. Sees to his men, where he can. Hence, me.’

He points at his chest. He has jug ears and a red face, fully freckled like Red John, and his arms hang from narrow shoulders almost to his knees. Katherine cannot help smiling at him.

‘Come on then,’ she says and together they help Richard from the wagon and into the barn.

‘Is there anything to eat?’ he asks.

There is a hunk of hard rye bread and a half-full leather bottle of thin ale, but that is all and when that is gone, they’ll have to think again. Together they help the walking wounded into the barn and then three grey friars from the friary join them, bringing with them long strips of linen, a glass jar of leeches, a selection of balms in clay pots, some rose oil, a tubby barrel of wine, six dozen eggs and a crucifix.

‘You deal with them,’ Katherine tells Mayhew.

At first they regard her with suspicion that only deepens when they see Richard sitting blank-eyed against the low stone course of the barn wall.

But then the wounded are brought in and laid in a line along the barn’s northern wall. Mayhew knocks out some of the crumbling infill in the southern wall to let in the day’s dying light, but it also lets in the cold, with flurries of snow, so they start a fire in the middle of the barn, burning what they can find, and soon the smoke is thick in the air and they are all red-eyed and coughing. They warm the wine and crack the eggs and Mayhew collects as much urine as he can. Then they unpack the surgeon’s instruments and start on the wounded, cutting away the clothing and washing the wounds with the urine and the hot wine.

Katherine’s first patient is a boy with an arrow in the meat of his thigh. He is pale with the fear of pain, and looks up at her with large eyes, soot-black and oily in the orange firelight. She studies the leg and considers him both lucky and unlucky. The arrow has not hit the bone. That is lucky. Nor has it hit the artery that carries all the blood, the one that when it is cut means a man will bleed to death.

But the arrow is buried deep in the muscle and the lips of the wound, now cleaned with a sponge, are pursed around the shaft of the arrow.

A shadow appears at her shoulder and she looks up.

‘May I?’