'Still hoping to seduce Himmler with this nonsense of manipulating history, are you?'

'We'll see if it's nonsense in due course,' Josef said, not offended.

'If your work's so important, what are you doing trailing all the way out here?'

'We're all stretched a bit thin these days, aren't we? Now that half the detachments stationed in Britain have been reassigned to the eastern front.'

'You know, I heard nothing about the war against Russia until this morning.'

Josef grinned. 'Well, neither did Stalin. It is in the east that the truth of this war will unfold, Ernst – not Germans against English or French, but the volk against the Slav. It is magnificent, they say. Three army groups are on the move, in a front a thousand miles long – think of it.' He winked at Ernst. 'But spare me from serving there!' He glanced back at Viv, who smiled at him. 'What do you think, shall I drive a bit faster and see if I can make her skirt ride up?'

'You are coarse, Josef.'

III

It was nearly noon by the time they reached the First Objective. In this region the line tracked the main road that ran up from Portsmouth through Petersfield to Milford, and then south of Guildford to Reigate. The barrier itself was a sculpture of wire and concrete that stretched from horizon to English horizon. Watchtowers and searchlight batteries loomed over the fences on both sides. Josef said, 'The shade of Emperor Hadrian himself would be awed by such a monument.'

This was the protectorate's demarcation line, which it was illegal for any subject of the occupation to call the 'Winston Line'. It cut off a slice of south-east England, running from Gravesend on the Thames estuary and south-west towards Portsmouth. The wall roughly corresponded to the first operational objective of Army Group A during the invasion, hence the name that had stuck to it among the German forces. The advance had been halted there when German stormtroopers found themselves facing Americans in their hastily erected bases. It had been Churchill's final masterstroke, in the panicky days after the invasion, to give away such bases to the US all along the objective line; in September 1940 the Reich was unwilling to go to war with America, and the Panzers' advance had stalled.

There was no armistice, and perhaps no possibility of one. England and Germany bombed each others' cities, a desultory campaign of misery – though wise heads said the 'blitz' would have been worse if not for the presence of German troops on English soil, and British subjects under German occupation. At sea, U-boat packs hunted down the supply convoys that crossed the Atlantic, and the Royal Navy harassed the much shorter supply lines to Albion from the continent. Overseas the war was being waged by proxy in a variety of theatres. In southern Europe Britain had opposed Hitler's assault on Yugoslavia and Greece, and Britain had defeated the Italians in Egypt, forcing Hitler to commit the Afrika Corps under Rommel. But once the initial German advance had been halted there had been little active fighting on the British mainland.

And so the situation had held, already for nine months, and the 'Winston Line' had solidified. London, to the north of the line, was in the territory held by the Halifax government, but it was a city held hostage by immediate peril. The government itself had evacuated to York. Ernst had once seen a newsreel of the line as filmed from the air at night. In a country plunged in blackout darkness, the First Objective was like a double wound, parallel lines of light slashed across the passive countryside, extending from coast to coast. It was a genuine division which bisected counties, severed towns from their suburbs, and cut families in two, often quite arbitrarily.

And yet Ernst, by nature an optimist, clung to the line as a symbol of hope. It was the one place where the British and the Germans, two nations at war, were managing to work together peacefully, finding solutions to benefit the most vulnerable. Perhaps the future could be built on such impulses, rather than war, occupation and conquest.

The convoy broke up. The vehicles pulled off the road onto concrete hard-standing areas, and the passengers jumped down. A bridge had been laid across the ditches here and a gate cut into the Objective. Civilians queued on both sides of the gate, waiting to be processed, men, women and children with bags and bicycles, prams and pets. Once the shock of invasion was over, there had been a mass movement of people back from the English territories into German Albion: refugees wanting to return to their homes, livelihoods and families.

Surrounded by soldiers, Viv was restless, increasingly nervous. A country girl, she had seen little even of the disruption military life had brought to the towns.

Josef got out of the car and took a slim briefcase from the boot. He pointed through the wire. 'See over there, the Stars and Stripes? That's the Americans. Shalford Base.'

'I fought my way here,' said Ernst. 'This is where the advance stopped, for me. This very spot.'

'I know. Few men got any further. That's why I brought you here. Look, the Swiss flag is flying over that camp too.'

'What have the Swiss got to do with it?'

'Protecting Power for the POWs.' He slapped Ernst on the shoulder. 'My business will probably only take a couple of hours. Look around. Enjoy your picnic with your little girlfriend. Which reminds me.' He dug inside his jacket. 'A letter for you. You might want to keep it from your sweetie over there.'

'Who's it from?'

He grinned. 'Your other lover. Claudine, was she called? It's good news. She's coming to England!'

'You read it?'

'Censorship, my boy. A military requirement. Behave yourselves, now.' And with a nod to Viv, he walked towards the gate.

Suddenly planes roared low overhead. Ernst flinched, a reflex that was a relic of the days when he had been under attack from the air. The planes were a schwarm of Messerschmitt 109s, patrolling the line on the German side. And there was a countering roar from the British side, Spitfires augmented by Mohawks of the USAAF.

IV

For all her bravado, Viv had been intimidated by the troops at the Objective, and the bored, mildly hungry looks they gave her. She stayed subdued all the way back to the farm. Ernst, Claudine's letter clutched closely to his heart inside his jacket, was distracted himself, and had little to say.

Viv brightened up once she and Ernst were back home. She practically skipped down the rough track to the farm. They were back not long after six o'clock, and the smell of the roast filled the house. Ernst went off to wash, relieved to be free of Viv for a few minutes. His room was the best in the farmhouse, with a view to the south; it had once been Fred and Irma's own bedroom. As he changed into a fresh shirt, he heard Viv brightly chattering about her day, how she had been chauffeured by an SS officer, and how she saw Americans through the wire like monkeys in a zoo. Elsewhere in the house Alfie was practising his violin. He played 'Lill Marlene'. On Saturdays he busked in Battle or Hastings, playing for pfennigs from homesick soldiers.

When Ernst came downstairs Fred was sawing away at the lamb joint with a carving knife that had been sharpened so often it had been reduced to a sliver of steel. Irma stood at the oven, stirring a pan of gravy. Plates heaped with vegetables, potatoes and cabbage, stood beside her. She looked quite exhausted.

Ernst produced one more present: a bottle of wine, imported by Wehrmacht stores from France. 'So we can toast the health of the King.'

'I'd prefer a beer,' Fred growled. But there had been very little beer about for many months; all of Albion's grain was requisitioned.