The vet touched the mare’s nose. When it steadied she peeled back its lips, studied the wetness of its eyes, paused a hand on each of its flanks. She gazed into its ears. She combed her fingers through its mane. Finally, she walked behind it to lift and bend its bad leg.

‘Fetch that,’ she said, pointing at a stump. Ned lifted it, struggled with the weight, heaved it over to her. She placed the mare’s raised foot on its surface and began studying the flat side of the hoof.

‘You’re William West’s youngest. From Limberlost.’

‘Yes, that’s right. I’m Ned.’

She gazed at the base of the hoof. The mare’s fetlock shook, but otherwise she was still. ‘There’s an impaction here,’ said the vet. ‘Get my chisel.’

She held out a hand. Ned fumbled into the shed, cast around for a veterinary chisel. He found an ordinary one, rusted and heavy. It seemed wrong, but he picked it up and handed it to the vet, who immediately turned it on the hoof.

Thick curls of dirty keratin rolled up from the gouging blade. The vet was attacking a deep groove in the centre of the hoof, furrowing in from a range of angles. More dead material peeled away, littering the garden like a whittler’s shavings. After a minute the vet stopped, stared at her work, placed the chisel on the ground.

‘Screwdriver. Flathead.’

Ned found one, this time not hesitating. The vet wedged it hard into the hoof and began applying force to the handle. The shaft of the screwdriver bent beneath her strength. She twisted, repositioned. Again the metal bowed. The vet grunted. The mare shook. To Ned, the world seemed paused in this moment of quiet pressure, as if the forest and garden were holding them still. Then a grating pop cut the air, the screwdriver snapped back into rigidity, and something flew from the hoof to land by the carrots.

Ned watched it hit the soil: a shard of rock half the size of his thumb. A dark liquid glossed its contours. As he watched light wink off its surface, a foulness rushed into his nostrils. A thick and fatty waft of rot. He flinched, staring at the shard, wondering at the horror of it, at how it could leak such poison into the air. It was only when he turned to the vet that he realised the rock wasn’t the source of the scent.