Once the raid started it went on and on, the planes rumbling across the sky, and the little shelter shuddered and rattled as the bombs slammed into the carcass of the town. Mary supposed the whole south coast was getting it, a final softening-up before the invasion forces landed.

Oddly she wasn't afraid. She had lived through too many raids.

When the others had gone running off to their posts, Mary had pulled on an overcoat, collected her bag and gas-mask, and went down to George Tanner's Anderson shelter. She got there just before the first planes came over. George had made the shelter a bright little place, like a den. He had painted the interior white, lined it with canvas to keep out the damp, and brought in blankets and deck chairs and a wireless set. There was even a camping stove to make a cup of tea. But the wireless delivered only static. Maybe the raids had knocked out the transmitting towers, silencing the BBC.

She had been back to the house a couple of times, trying to remember what needed to be done. She'd turned off the lights, switched off the gas, and filled sinks and the bathtub with water in case the mains got cut off. She had her briefcase with her research materials, and she packed a small rucksack with clothes and bathroom stuff. But then it was back to the shelter. She felt useless stuck down here, contributing nothing.

There were safer places to be than this. The best shelter in Hastings was a system of caves called St Clement's, which had been fixed up to hold a few hundred. And it would be safer yet to get out of town altogether and head off inland, where she could evade both the bombs today and, presumably, the stormtroopers that were likely to land here tomorrow.

But she didn't want to leave the house. This was the last point where they had all been together, she and her son, his new wife and her father, and even poor sweet Ben. She wished she had thought to arrange a way they could contact each other.

It occurred to her that even if the house was bombed flat, as seemed highly likely right this minute, the Anderson shelter might survive. Here, then. She scrabbled in her bag for her lipstick. It was an American brand, and she used it sparingly; cosmetics were just one item in desperately short supply over here. She made an experimental mark on the white-painted wall. The lipstick was bright red; you couldn't miss it, and, in the interior of the shelter, it wasn't likely to get washed off or rubbed away.

But where should she tell them to meet? Nowhere in Hastings itself; the place would be crawling with Germans if they landed. Somewhere nearby, somewhere memorable. She held up her lipstick, and wrote clearly:

It was just as she dropped the lipstick back in her bag that the big bomb fell.

Ben and Hilda had driven off in Mary's car, her rented Austin Seven. Hilda had to get to her radar station, and Ben to his Home Guard assignment at Pevensey.

With Hilda at the wheel they barrelled along the coast road, heading west through Bexhill and onwards. They drove past the long fortified beaches with their huge coils of barbed wire and emplacements of superannuated Navy guns. The traffic was heavy, as the men of the Home Guard and the army detachments struggled to get to their pillboxes and machine-gun nests, and WAAFs and Wrens hurried to their naval gun emplacements. But the road was clogged with civilians, fleeing from the towns. There were a few cars, and carts drawn by horses and donkeys, amid files of pedestrians pushing prams and wheelbarrows heaped up with luggage and furniture. All of this got in the way of the military vehicles, and of the ambulances straining to get through.

Overhead, a war was being fought out in the air, Messerschmitts and Spitfires and Hurricanes tearing into each other over fleets of German bombers. Nobody looked up to watch.

Hilda grunted and swore as she rammed the car through the clogged traffic. Ben could see the ring on her finger, her mother's ring, just a little too big for her; Hilda, focused, seemed to have forgotten it was there.

'So, Pevensey,' she said. 'We'll reach my radar station first.'

'I can drive on from there. I'm a lousy driver, but I know the way.'

'It's an observation post, yes?'

'And a defensive point, and a headquarters… There are a bunch of Canadians there. They fortified the old castle. I'm surprised your radar station is still operational.'

She glanced at him. 'I suppose it doesn't matter if I tell you now. The RAF is withdrawing, moving the fighters back from the forward bases. They'll operate from deeper inland now. Before sunset we'll have to decommission my station. Scrap the gear if we can't bring it back out of the threatened zone. Well, here we are.'

She lurched off the road, throwing Ben sideways.

An unprepossessing station lay ahead, locked behind a fence of barbed wire. Ben glimpsed masts, seven or eight of them, hundreds of feet high, and blocky buildings. The station had already taken damage, Ben saw; part of the fence had blown down.

'This is it. Good luck.' Leaving the engine running, Hilda leaned over, kissed him on the cheek, and hurried out of the car. Then she was gone, off at a run to her station.

'You too,' Ben murmured. He slid across to the driver's seat. He gave himself thirty seconds to familiarise himself with the strange controls of this English car. Then he turned the car around with a squeal of tyres and rejoined the traffic stream, heading west towards Pevensey.

Hot air pulsed over Mary, a compression that squeezed her chest. The whole shelter lifted and shuddered, and bits of stuff, the wireless and the tin cups, rattled and fell off their shelves. The shelter's roof clattered, as if handfuls of gravel were being dropped on it.

But the noise was muffled. She touched her ears to see if they had been stopped up by dirt or dust. They were clear. She could hear little but a ringing noise.

It made her mind up. Whatever came next, she couldn't just sit in here, waiting to be bombed out. She had her handbag with her papers, and all her cash, her gas-mask, her rucksack, her briefcase. She glanced around the shelter. She picked up the camping stove and set it carefully on the floor.

Then she clambered up the little ladder and emerged into George's garden. The soil, and George's potatoes and carrots, were covered in debris, bits of brick, wood slats, slates, and a layer of dust. There was heat in the air, and a smell of dust and sewage. Yet she could still hear little. The planes washing overhead sounded dull and distant.

She made her way through the house and out to the street. She locked George's front door carefully behind her.

She walked down the street, heading for the sea front. This was Hastings' Old Town, a tangle of streets crammed into a valley between two sandstone hills, steep and crowded, long terraces of houses assembled over centuries. Today there was chaos, brick and broken glass spilled all over the road, people running, distant screaming.

She found that the big bomb had fallen slap bang on top of a large corner house on the High Street. Mary just stood and stared. A crater had been dug deep into the ground, and broken pipes and cables jutted out like snapped bones. The house itself had been sliced open, exposing the interiors of rooms, so it looked like an immense doll's house. In one upper storey room a big iron bed dangled perilously over the drop. There was an extraordinary, repellent stink, of dust, ash, burned meat, sewage.

People swarmed all over the smashed house. A fire tender was pulled up outside, and firemen grappled with a hose, spraying the lower floors with water. Men of a Heavy Rescue Squad were hauling their way through heaps of brick, trying to get through to rooms at the back of the house. Some worked with bare hands, and others laboured to get joists and blocks and tackles in place, to lift heavier beams and slabs of wall. They were already streaked with dirt and sweat.