The last time she’d been on the water was at the artificial lake in Christchurch Park, when she’d found the instability of the little rowing boat unnerving. But this ship felt so steady beneath her feet it was hard to believe they were not still on dry land. A huge grey and white seagull landed on the railing just ahead of her, cocking its head to one side, interrogating her with a piercing yellow eye.

‘Hello, bird,’ she said. ‘I haven’t got anything to give you, I’m afraid.’

Men far below on the quayside began to wheel the wooden gangways away from the side of the ship. Great coils of rope, thick as a man’s arm, were slung from either end and hauled in by waiting groups of navvies. Their shouts were drowned by a sudden ear-splitting blast of the ship’s horn that seemed to reverberate through her body. The gull flew off, leaving a white splat on the high polish of the hand rail.

A single downy feather fluttered to the deck and she picked it up, turning it in her fingers, marvelling at its delicacy. But then she recalled, at the start of the war, reading reports of women handing out feathers like this, shaming men into joining up. She shivered and dropped it quickly. She’d rather Bertie had been called a coward and come home with one of these than with his call-up papers. At least he’d have been alive.

Almost imperceptibly at first, and then more quickly, the ship moved away from the dockside. Beside her, fellow travellers waved to their friends gathered below, calling farewells. They gathered speed swiftly, passing through the mouth of the docks and into the open sea. As the breeze picked up most of the passengers retired below, but Ruby was determined to watch the land as it receded. This would have been Bertie’s last view of England, and she owed it to him to look until it disappeared. What would have been in his mind, that day? Was he worried or frightened? Did he wonder when he would get to see those white cliffs again?

Or perhaps his mood was buoyed by the excitement of the journey, of the new sights and sounds. He’d have been with his mates, after all; they would have been jollying each other along and cracking jokes, of course. At school they’d called him the class clown. It cheered her to imagine how the other men would have come to love his impertinence, his generosity – always sharing his fags – and how he’d have made them laugh.

It was late afternoon and the intense whiteness of the chalky cliffs, illuminated by the sun, formed a wide luminous band, almost unearthly, along the edge of the land separating grey sea and blue sky. She stood, transfixed, as the ship pulled steadily away.

‘Quite a sight, ain’ it?’

The voice, with its unmistakeable American twang, made Ruby jump. She’d thought herself alone on the deck. She looked up into the eyes of the tall movie-star woman she’d observed getting onto the train. Bright scarlet lips smiled widely to reveal the largest, whitest teeth Ruby had ever seen.