'From Dunkirk to Berlin, eh?' Mackie murmured. 'Good for you.'

The girl came over and took Mary's order. No older than sixteen or seventeen, she wore rouge, eye liner, lipstick, and what looked like real stockings. Pushing back through the tables she ran a gauntlet of leers, whistles and wandering hands.

'Remarkable,' Mackie said, watching her go. 'Here we are not half a mile from the seat of Halifax's government, and there's a girl like that, a walking demonstration of the way the GIs have distorted the British economy, with their ration-busting cigarettes and sweets and silk stockings, all pumping up the black market – their rather coarse glamour-'

Gary laughed and sipped his tea. 'You sound as if you'd like to be rid of your allies, Captain. How did Churchill put it? You'd carry on the fight until, in God's good time, the new world, with all its power and might, steps forth to the rescue and the liberation of the old". Well, here we are.'

'Yes, thanks very much. And the sooner we get you lot packed off back to the land of the free the better.'

'I'll drink to that.'

'Let's get down to business.' Mackie said to Mary, 'We need to talk more fully. But I've already given Gary an outline of what we're up to. And an indication of the role I'd like him to play.'

Gary eyed her. 'History books and time machines!'

Mackie glanced around uneasily. 'Walls have ears and all that, old chap.'

'Well, all right.' Gary spoke more quietly. 'Look, Mom, Captain Mackie got me seconded to his operation, though I have an assurance it won't be until W plus three.'

'W"?'

'W-Day,' Mackie said with a cold grin. 'Operation Walrus. Eats sea lions. One of Churchill's.'

Gary said, 'I'm struggling to believe that I'll be more use following up this fruitcake stuff than I would be with my buddies kicking Nazi butt around Sussex and Kent.'

Mary nodded. 'I understand. I generally have trouble believing it myself. But I do have evidence, Gary.'

'Historical stuff.'

'Yes. That's what I'm here to discuss with the Captain, in fact. I've spent three years on this now, on and off. The likelihood of this project of the Germans coming off might seem low. But if it did, the consequences could be – well, catastrophic.'

Gary frowned. 'If you weren't my mother I'd walk out of here right now. You hear too much of this guff about Hitler's secret super-weapons.'

Mackie said, 'I've made it plain to Gary that he's under no obligation to carry this through. Indeed he's under no obligation to return to front-line combat at all.'

'I don't want a damn staff job,' Gary said fiercely. 'That would kill me off faster than any Nazi bullet.' Mary flinched, and he was instantly regretful. He covered her fingers with his. 'Mom, I'm sorry. But you can see how it is. Especially as we're so close to the off. Or so I heard.' He drained his tea, and swept up the last of the cakes from the plate and stuffed them in his pocket, an old prisoner's reflex. 'Listen, I got to go. I do wish we could have had more time, Mom.' He leaned over to give her another hug; he let her hold him for a long minute. When they broke he said, 'I'll tell you what. If I were going to go back and fix the past to resolve this damn war, I know where I'd go.'

'Where?'

'Versailles. The lousy settlement after the first war. You speak to any German, and I spoke to enough in the stalag, and he'll tell you that's where it all began. A just peace and you'd get no Hitler.'

Mackie murmured, 'I'll take it on advisement.'

'You do that.' Gary stood and took his gas-mask pouch from the back of his chair. 'Good day, Captain. Mom.'

'Godspeed, son.'

He walked away. Once outside the shop he fixed his cap on his head, straightened up and marched off. She watched him until he was out of sight.

Mackie waited patiently. 'He's a good young man. I'm sure he'll fulfil the mission we have for him.'

'I just want him to get through all this without getting shot up again.'

He tapped his saucer with a clean fingernail. 'Look, let's wait for your tea. Then perhaps we should get out of here. I think I'd feel more comfortable if we talked on the hoof, so to speak.'

Mary sat back. 'Come on, Tom. You can't seriously believe there's a German spy in here. We're surrounded by GIs!'

Mackie grunted. 'Believe you me, there are circles in the British government who are more wary of our allies than our enemies. No offence. Where is that girl?'

IV

So they walked, heading through the heart of the city towards the minster.

It was a hot June day, a little after three. In the centre of the city the shops were busy, the place bustling even on a Friday afternoon, full of military and pinstripe-suited civil service types. A British Restaurant, a self-service cafe ostensibly for the use of the bombed-out, was doing brisk business. Mackie and Mary, both bookish, paused by a W.H. Smith's whose window was piled high with Penguin editions of Graham Greene and Agatha Christie novels, and pot-boiler crime and romance.

It was the GIs who caught the eye, though. You saw them everywhere, hanging around on street corners like unruly kids, endlessly chewing gum, and ostentatiously smoking their Camels and Lucky Strikes at a time when smokers in England mostly had to put up with foul Turkish brands. They had a kind of loose casualness about them that was just this side of slovenly, and it made you realise how prim and proper most British servicemen looked by comparison. In England's cities and towns, 1943 would always be remembered as the GI summer, Mary thought.

York was busier than most towns in free England, because it was the emergency seat of government. But it shared with the rest the marks of the long war: the ack-ack gun emplacements, the pillboxes, the sandbags around the public buildings. The major air campaigns had been abandoned after those frenetic months of the invasion in 1940, but because it was the seat of government York had taken more than its share of the sporadic Luftwaffe raids – the Brits called them 'tip and run' raids. So there were gaps in the streets, marked by stubs of walls and broken pipes, the rubble cleared away and piled up in vast mounds in the parks. Some of these bomb sites were four years old and were choked with greenery; the weeds loved the brick dust and the ash. Mary supposed glumly that when W-Day came the bombing would resume in Britain, just as it was about to resume, so she'd heard, in the heart of Germany, and that York and other cities would soon have fresh scars to add to the old.

Some of the changes wrought by the war seemed positively medieval. Every park, playing field and flower bed was given over to growing crops or raising pigs: it must have been five hundred years, Mary mused, since the farmyard had penetrated the city in such a way. And there was a pervasive atmosphere of neglect. The city was stripped of railings and lamp-posts, the metal turned over to the armaments industry. After nearly four years without a lick of fresh paint the homes and shops and offices looked shabby, slowly decaying, their blacked-out windows like closed eyes. Mary thought she saw a similar round-shouldered shabbiness in the people, in their patched-up clothes and shoes, now enduring the fourth year of a war that had become, worse than grinding, boring.

The most spectacular bomb site of all was the minster itself. In one week in the summer of 1942 the Luftwaffe had launched a series of particularly spiteful raids against the grand old building, evidently meaning to make a symbolic strike against Halifax's seat of power. When they reached it, Mary and Mackie stepped cautiously through the main entrance on the northern side, with flags of St George, Britain, the United States, Poland and France flying over their heads, and into the shadow of ruin. The central tower had been pretty much demolished, and the rest of the roof was blown in, the stone floors smashed to shrapnel. But the minster was still a working church. A small open-air altar had been set up beneath the Great West Window which had, by luck or a miracle, survived the bombing. But most of the interior, cleared of rubble and swept for unexploded shells, had been dug up to form allotments. Today squads of Land Girls toiled in the shadows of the broken walls.