Then it is over. They sigh and subside, the twitchings and stirrings cease, they lie at rest side by side drifting off into sleep, while unhappy, rigid, wide awake, I wait my chance to escape. It is the hour when even the chickens doze, the hour when there is only one emperor, the sun. The heat in this tiny room under the flat roof has grown stifling. I have not eaten or drunk all day.

Pushing with my feet against the wall, I edge out till I can gingerly sit up. The pain in my back, an old man's pain, announces itself again. "I am sorry," I whisper. They are truly asleep, like children, a boy and a girl, naked, hand in hand, beaded with sweat, their faces relaxed and oblivious. The tide of shame sweeps over me with redoubled force. Her beauty awakes no desire in me: instead it seems more obscene than ever that this heavy slack foul-smelling old body (how could they not have noticed the smell?) should ever have held her in its arms. What have I been doing all this time, pressing myself upon such flowerlike soft-petalled children-not only on her, on the other one too? I should have stayed among the gross and decaying where I belong: fat women with acrid armpits and bad tempers, whores with big slack cunts. I tiptoe out, hobble down the stairs in the blinding glare of the sun.

The upper flap of the kitchen door stands open. An old woman, bent and toothless, stands eating out of a cast-iron pot. Our eyes meet; she stops, the spoon in mid-air, her mouth open. She recognizes me. I raise a hand and smile-I am surprised at how easily the smile comes. The spoon moves, the lips close over it, her gaze shifts, I pass on.

The north gate is closed and barred. I climb the stairway to the watchtower over the angle of the wall and stare out hungrily over the beloved landscape: the belt of green stretching along the river, blackened now in patches; the lighter green of the marshes where the new reeds are shooting; the dazzling surface of the lake.

But there is something wrong. How long have I been locked away from the world, two months or ten years? The young wheat in the acres below the wall ought by now to be a vigorous eighteen inches high. It is not: except at the western limit of the irrigated area the young plants are a stunted sickly yellow. There are great bare patches nearer the lake, and a line of grey stooks by the irrigation wall.

Before my eyes the neglected fields, the sunstruck square, the empty streets shift into a new and sinister configuration. The town is being abandoned-what else is there to suppose?-and the noises I heard two nights ago must have been noises not of arrival but of departure! My heart lurches (with horror? with gratitude?) at the thought. Yet I must be mistaken: when I look down more carefully at the square I can see two boys quietly playing marbles under the mulberry trees; and from what I have seen of the inn, life is going on as usual.

In the south-west tower a sentry sits on his high stool staring vacantly into the desert. I am within a pace of him before he notices me and starts.

"Get down," he says in a flat voice, "you are not allowed up here." I have never seen him before. Since I left my cell, I realize, I have not seen one of the soldiers who made up the old garrison. Why are there only strangers around?

"Don't you know me?" I say.

"Get down."

"I will, but first I have a very important question to ask you. You see, there is no one to ask but you-everyone else seems to be asleep or away. What I want to ask is: Who are you? Where is everyone I used to know? What has happened out there in die fields? It looks as though there has been a washaway. But why should there be a wash-away?" His eyes narrow as I gabble on. "I am sorry to ask such stupid questions, but I have had a fever, I have been confined to bed"-the quaint phrase comes unbidden-"and today is the first day I have been allowed to get up. That is why…"

"You must be careful of the midday sun, father," he says. His ears stick out under a cap that is too large for him. "You would be better off resting at this time of day."

"Yes… Do you mind if I have some water?" He passes me his flask and I drink the lukewarm water, trying not to betray how savage my thirst is. "But tell me, what has happened?"

"Barbarians. They cut away part of the embankment over there and flooded the fields. No one saw them. They came in the night. The next morning it was like a second lake." He has stuffed his pipe, now he offers it to me. Courteously I decline ("I will only begin coughing, and that is bad for me"). "Yes, the farmers are very unhappy. They say the crop is ruined and it is too late to plant again."

"That's bad. It means a hard winter ahead. We will have to draw our belts very tight."

"Yes, I don't envy you people. They could do it again, couldn't they, the barbarians. They could flood these fields any time they chose to."

We discuss the barbarians and their treachery. They never stand up and fight, he says: their way is to creep up behind you and stick a knife in your back. "Why can't they leave us alone? They have their own territories, haven't they?" I turn the conversation to the old days when everything used to be quiet on the frontier. He calls me "father", which is his peasant's way of showing respect, and listens to me as one listens to mad old folk, anything being better, I suppose, than staring out into emptiness all day.

"Tell me," I say: "two nights ago I heard horsemen and thought the big expedition had returned."

"No," he laughs, "those were just a few men they sent back. They sent them in one of the big carts. That must have been what you heard. They fell sick from the water-bad water out there, I hear-so they sent them back."

"I see! I couldn't understand what it was. But when do you expect the main force back?"

"Soon, it must be soon. You can't live on the fruit of the land out here, can you? I've never seen such dead country."

I climb down the steps. Our conversation has left me feeling almost venerable. Strange that no one warned him to watch out for a fat old man in ragged clothes! Or has he perhaps been perched up there since last night with no one to speak to? Who would have thought I could lie so blandly! It is mid-afternoon. My shadow glides beside me like a pool of ink. I seem to be the only creature within these four walls that moves. I am so elated that I want to sing. Even my sore back has ceased to matter.

I open the small side gate and pass out. My friend in the watch-tower looks down at me. I wave, and he waves back. "You will need a hat!" he calls. I pat my bare skull, shrug, smile. The sun beats down.

The spring wheat is indeed ruined. Warm ochre mud squelches between my toes. In places there are still puddles. Many of the young plants have been washed right out of the ground. All show a yellowish discoloration of leaf. The area nearest the lake is the worst hit. Nothing is left standing, indeed the farmers have already begun to stack the dead plants for burning. In the far fields a rise of a few inches in elevation has made all the difference. So perhaps a quarter of the planting can be saved.

The earthwork itself, the low mud wall that runs for nearly two miles and keeps the lake-water in check when it rises to its summer limit, has been repaired, but almost the whole of the intricate system of channels and gates that distributes the water around the fields has been washed away. The dam and waterwheel by the lakeshore are unharmed, though there is no sign of the horse that usually turns the wheel. I can see that weeks of hard work await the farmers. And at any moment their work can be brought to nothing by a few men armed with spades! How can we win such a war? What is the use of textbook military operations, sweeps and punitive raids into the enemy's heartland, when we can be bled to death at home?