«Eric!» I yelled, as the door gave way. He held the axe with one hand, picked up the torch with the other; he kicked the door and it fell. I tensed the catapult one final centimetre. I gazed at him through the Y of the catapult's arms. He looked at me. His face was bearded, dirty, like an animal mask. It was the boy, the man I had known, and it was another person entirely. That face was grinning and leering and sweating, and it beat to and fro as his chest heaved in and out and the flames pulsed. He held the axe and the burning brand, and the cellar door lay in a wreck behind him. I thought I could just make out the bales of cordite, darkly orange in the thick and shivering light from the fires around us and the torch my brother held. He shook his head, looking expectant and confused.

I shook my head, slowly.

He laughed and nodded, half-dropped, half-threw the torch into the cellar, and ran at me.

I almost released the steelie as I saw him come at me through the catapult, but just in the last second before my fingers opened I saw he had dropped the axe; it clattered off the steps to the cellar as Eric dodged past me and I dropped and ducked to one side. I rolled, saw Eric haring away over the garden, heading south down the island. I dropped the catapult, ran down the steps and picked the torch up. It was a metre into the cellar, nowhere near the bales. I threw it outside quickly as the bombs in the blazing shed started to go off.

The noise was deafening, shrapnel whizzed over my head, windows in the house blew in and the shed was totally demolished; a couple of bombs were blown out of the shed and exploded in other parts of the garden, but luckily none came near me. By the time it was safe for me to raise my head the shed no longer existed, all the sheep were dead or gone, and Eric had vanished.

My father was in the kitchen, holding a pail of water and a carving-knife. I came in and he put the knife down on the table. He looked about a hundred years old. On the table was the specimen-jar. I sat down at the head of the table, collapsing into the chair. I looked at him.

"That was Eric at the door, Dad," I said, and laughed. My ears were still ringing from the explosions in the shed.

My father stood looking old and stupid, and his eyes were bleary and wet and his hands shook. I felt myself calm down, gradually.

"Wha-" he began, then cleared his throat. "What… what happened?" He sounded almost sober.

"He tried to get into the cellar. I think he was going to blow us all up. He's run off now. I've put the door back up as best I can. Most of the fires are out; you won't need that." I nodded at the pail of water he held. "Instead I'd like you to sit down and tell me one or two things I'd like to know." I sat back in my chair.

He looked at me for a second, then he picked up the specimen-jar, but it slipped from his fingers, fell to the floor and smashed. He gave a nervous laugh, bent, and stood back up holding what had been inside the jar. He held it out for me to see, but I was looking into his face. He closed his hand, then opened it again, like a magician. He was holding a pink ball. Not a testicle; a pink ball, like a lump of plasticine, or wax. I stared back into his eyes.

"Tell me," I said.

So he told me.

ONCE, far south, past even the new house, I went to build some dams amongst the sand and the rock pools on that part of the coast. It was a perfect, calm, luminous day. There was no line between the sea and the sky, and any smoke rose straight. The sea was flat.

On the land in the distance there were some fields, set on to a mildly sloping hillside. In one field there were some cows and two big brown horses. While I was building, a lorry came down a track by the field. It stopped by the gate, reversed and turned so that its rear was facing me. I watched through the binoculars as this went on about half a mile away. Two men got out. They opened the back of the truck so that a ramp was formed into its interior, wooden slatted sides being folded out to make fences on either side of the ramp. The two horses came to watch.

I stood in a rock pool, water round my wellingtons, and I cast a watery shadow. The men went into the field and led one of the horses out, a rope round its neck. It went out with no complaint, but when the men tried to get it to go into the truck, up the tailboard, between the skewed, slatted sides, it shied and refused, leaned backwards. Its mate pressed against the fence beside it. I heard its cries, seconds late through the still air. The horse would not go in. Some cows in the field looked on, then continued munching.

Tiny waves, clear folds of light, consumed the sand, rock, weed and shell beside me, lapping quietly. A bird called in the calmness. The men moved the truck away, led the horse after it, down the track and along an offshoot of it. The horse in the field cried out, and ran in pointless circles. My arms and eyes grew tired, and I looked away, at the line of hills and mountains marching into the glowing light of the north. When I looked back they had the horse inside the truck.

The truck moved off, wheels spinning briefly. The lone horse, confused again, ran from gate to fence and back again, first following the truck, then not. One of the men had stayed behind in the field with it, and as the truck disappeared over the brow of the hill he calmed the animal.

Later, on my way back home, I passed the field with the horse in it, and it was quietly cropping the grass.

I am sitting on the dune above the Bunker now, in this fresh, breezy Sunday morning, and I am remembering dreaming about that horse last night.

After my father told me what he had to tell me, and I passed through disbelief and fury to stunned acceptance, and after we had a look round the outskirts of the garden, calling for Eric, cleaning up the mess the best we could and putting out the remaining small fires, after we barricaded the cellar door and went back to the house and he told me why he had done what he had, we went to bed. I locked my bedroom door, and I'm pretty sure he locked his. I slept, had a dream in which I relived that evening of the horses, then woke early and went out, looking for Eric. I saw Diggs coming down the path as I left. My father had a lot of talking to do. I left them to it.

The weather had cleared. No storm, no thunder and lightning, just a wind out of the west sweeping all the cloud away out to sea, and the worst of the heat with it. Like a miracle, though more likely just an anticyclone over Norway.

So it was bright and clear and cool.

I found Eric lying asleep on the dune above the Bunker, head in the swaying grass, curled up like a little child. I went up to him and sat beside him for a while, then spoke his name, nudged his shoulder. He woke up, looked at me and smiled.

"Hello, Eric," I said. He held out one hand and I clasped it. He nodded, still smiling. Then he shifted, put his curly head on my lap, closed his eyes and went to sleep.

I'm not Francis Leslie Cauldhame. I'm Frances Lesley Cauldhame. That's what it boils down to. The tampons and the hormones were for me.

My father dressing Eric up as a girl was just, as it turned out, a rehearsal for me. When Old Saul savaged me, my father saw it as an ideal opportunity for a little experiment, and a way of lessening — perhaps removing entirely — the influence of the female around him as I grew up. So he started dosing me with male hormones, and has been ever since. That's why he's always made the meals, that's why what I've always thought was the stump of a penis is really an enlarged clitoris. Hence the beard, no periods, and all the rest.