Her voice had dropped, become contemplative. She realised that for several minutes she had forgotten to feel sick. She sat up a bit. ‘Don’t you think?’

Something odd happened to Frances’s expression: it closed over, became neutral, mask-like. ‘I suppose so,’ she said.

And Avice knew she might as well have said that the sky had gone green. She felt unbalanced and irritated, as if her gesture towards intimacy had been deliberately rebuffed. She was almost tempted to say something to that effect but at that moment Margaret waddled back to the table bearing a tea tray. Propped in her mug was a large vanilla ice-cream, the third she had eaten since they had sat there.

‘Listen to this, girls. Old Jean will love it. There’s going to be a crossing-the-line ceremony. It’s a sailors’ tradition, apparently, about crossing the equator, and there’s going to be all sorts of fun on the flight deck. The guy at the tea urn just told me.’

Frances’s rudeness was forgotten. ‘Will we have to get dressed up?’ Avice’s hand had risen to her hair.

‘Dunno. I know nothing about it – they’re going to post something on the main noticeboard later. But it’ll be a laugh, right? Something to do?’

‘Ugh. I’m not joining in. Not with my stomach.’

‘Frances?’ Margaret had bitten the top off her cone. A small blob of ice-cream was stuck to the tip of her nose.

‘I don’t know.’

‘Ah, come on,’ said Margaret. The chair creaked in protest as she sat down. ‘Let your hair down, woman. Cut loose a little.’

Frances gave her a tentative smile, showing small white teeth. She might even, Avice saw, with a start, be beautiful. ‘Perhaps,’ she said.

Frances had thought she would resent the man outside. On the first night he had stood there, on the other side of their door, she had been unable to sleep, conscious of the stranger’s proximity. Of her own state of undress, her vulnerability. Of the fact that, in theory at least, he was in authority over her. She had been acutely conscious of his every movement, every shift of his feet, every sniff or cough, the sound of his voice as it murmured a greeting or instruction to a passer-by. Occasionally, lying in the dark, she would ponder on his significance: his presence highlighted the fact that they were cargo, a consignment to be ferried safely from one side of the world to the other, in many cases from fathers to husbands, one set of men to another.

Those heavy feet, that rigid stance, the rifle told her they were to be constrained, imprisoned, yet guarded, protected from the unknown forces below. Sometimes, when the nearness of so many people, so many strange men, teamed with their isolation made her feel anxious, she was glad that he was stationed outside the door. But more usually she resented him for making her feel like a possession, someone’s property to be safeguarded.

The others seemed to indulge in little such philosophical consideration. In fact, they didn’t notice him; for them, like so much on board, he was part of the nightly furniture, someone to call good evening to, to smuggle the dog past, or even themselves, if they were tiptoeing downstairs to another party. As they were tonight. Margaret and Jean were off to meet Dennis for another poker session, chatting in surreptitious whispers as they brushed their hair, fiddled with stockings and shoes and, in Jean’s case, borrowed everyone else’s cosmetics. It was nearly nine, not late enough to confine them to their cabin, according to the curfew, but after both supper shifts: late enough to warrant a legitimate query about where they were going, should their movement be noticed.

‘You sure you won’t come with us, Frances?’ They had been to several parties now. Jean had stayed sober during at least one.

Frances shook her head.

‘You don’t need to behave like a nun.’ Margaret finished doing up her shoe. ‘I’m sure your old man won’t mind you enjoying a bit of company, for goodness’ sake.’

‘We won’t tell,’ said Jean, shaping her mouth into a moue as she reapplied her lipstick.

Margaret lifted her dog on to what remained of her lap. ‘You’ll go nuts if you spend every evening in here, you know.’

‘They’ll have to walk you off in a straitjacket when we get to Plymouth.’ Jean cackled, tapping the side of her head with a forefinger. ‘They’ll think you’ve got kangaroos loose in the top paddock.’

‘I’ll take my chances.’ Frances smiled.

‘Avice?’

‘No, thank you. I’ll rest this evening.’ Avice’s nausea had worsened again, and she lay, pale and limp, on her bunk, periodically lifting and lowering her book. ‘If you could keep the dog well away from me I’d be grateful. Its smell is making me feel even worse.’

They had not expected the marine to be standing outside. He had not been there the previous evening, and none of them had heard the footsteps that usually signalled his arrival. Jean, then Margaret, stopped dead in the doorway. ‘Oh . . . we’re just going for some fresh air,’ said Margaret, speedily closing the door behind her.

‘We’ll be back by eleven,’ said Jean.

‘Or thereabouts.’

Frances, who had stood up to retrieve her dressing-gown from a hanger, paused on the other side of the door, hearing the male voice, the surprise and slight strain in the women’s.

‘I’d avoid the Black Squad, if that’s how you like your fresh air,’ he said now, so quietly that no one could be sure of what they’d heard.

Frances leant closer to the door, her dressing-gown raised in the air.

‘The stokers’ mess. Bit of a crackdown tonight,’ he explained.

‘Oh. Right,’ said Margaret. ‘Well. Thanks.’

She heard their shoes clattering down the passageway, then the marine coughing quietly. They would say nothing until they reached the corner by the fire hose. Then, out of sight, they would explode with shock and laughter, clutching each other briefly before, with a furtive glance behind them, they made for the stokers’ mess.

Avice wasn’t asleep. It would have been easier, Frances thought, if she had been. Stuck together in the little cabin, they moved silently around each other. Then Avice lay down, facing the wall, and Frances flicked self-consciously through a magazine, hoping her concentration appeared more genuine than it was.

They had rarely spent any time alone together. Margaret was easy, straightforward, her uncomplicated nature written in her ready smiles. Jean was less predictable, but there was no side to her: she expressed everything she felt, every minor irritation and enthusiasm directly, unpalatable as it might be.

But Avice, Frances guessed, found her difficult. Not only did they have nothing in common, but her personality, her way of being, rubbed Avice up the wrong way. She suspected that in other circumstances Avice might have been openly hostile: experience had shown her that that kind of girl often was. They needed to look down on someone to reassure themselves of their own position.

But there was no room for such honest emotion in a cabin not quite ten feet by eight. Which left the two of them locked in their own excruciating worlds of genteel diplomacy. Frances would enquire occasionally whether Avice needed anything, whether her sickness had lifted a little; Avice would ask if Frances minded her leaving the light on a little longer; both would spend the rest of the evening pretending politely that they believed the other to be asleep.

Frances lay back on her bunk. She tried to read, found she had scanned the same paragraph several times without taking anything in. She forced herself to concentrate and discovered she had read the magazine before. Finally she stared up at the sagging webbing above her, watching it shift.

The dog whimpered quietly in sleep, just visible under Margaret’s cardigan. She glanced down to check that its water bowl was full.

Way above them, she heard a bump, followed by a muffled burst of laughter.

Outside, the marine muttered to someone as they passed. Time stretched out, became elastic.

Frances sighed. Quietly, so that Avice would not hear. Margaret was right. If she spent another evening in here, she’d go insane.

He turned when she opened the door. ‘Stretching my legs,’ she said.

‘Strictly speaking, ma’am, you shouldn’t be leaving your cabin at this time.’

She didn’t protest, or plead, just stood, waiting, and he nodded her on. ‘Stokers’ mess?’

‘No,’ she said, smiling at her feet. ‘No. Not my cup of tea.’

She walked briskly along the passageway, conscious of his eyes on her back, fearful that he might call out to her that he had changed his mind, that it was already too close to the curfew, and instruct her to stay where she was. But he said nothing.

Out of his range, she went up the stairs near the cinema projection room, nodded a polite greeting to two girls who, arm in arm, stood back to let her pass. She hurried along, head down, past cabins, past rows of tin trunks secured to the wall with webbing straps, the redundant stores for lifejackets, weaponry, ammunition, the painted instructions – ‘Keep Dry’, ‘Do Not Use After 11.47’, ‘Do Not Smoke’. She strode up the temporary steps towards the captain’s sea cabins two at a time, ducking to avoid hitting her head on the metal struts.

She reached the hatch, glanced back to check no one was watching, then opened it and stepped out on to the flight deck. Then she stopped abruptly, almost reeling from the sudden expanse of inky black sea and sky.

Frances stood there for some time, breathing in the cool, fresh air, feeling the breeze tighten the skin of her face, enjoying the gentle movement of the ship. Down below the throbbing of the engines often made her feel as if she was in the bowels of some prehistoric animal: it vibrated through her, chugging and groaning bad temperedly with effort. Up here, the movement was a low purr, the creature benign and obedient, carrying her safely forward, like some mythical beast, across the vast ocean.

Frances peered across the deserted deck, out of bounds after dark. Some moonlit, some in shadow, the silhouettes of the aircraft stood around her, like children congregated in a playground. There was something oddly appealing about their profiles, noses up, as if they were scenting the air. She walked slowly among them, allowing herself to stroke the shining metal, relishing its cool, damp feel under her hand. Finally, she sat down under a narrow streamlined belly. In her vantage-point on the concrete floor, between two webbing lashes, she folded her hands round her knees and stared out at the million stars, the never-ending trails of white foam that charted their course through the water, the unknowable point where the inky sea met the infinite black sky. And for possibly the first time since they had embarked, Frances Mackenzie closed her eyes and, with a shudder that passed through her entire body, allowed herself to breathe out.

She had been sitting there for almost twenty minutes when she saw the captain. He had stepped out of the same door she’d closed behind her, his rank clearly visible in his white cap and his curiously accentuated upright posture. She recoiled at first, and manoeuvred herself so that she was protected by the shadows, already anticipating the choleric shout ‘Hey! You!’ that would bring about her disgrace. She watched him close the door carefully so that it did not slam. Then, with the same furtive air as, presumably, she had displayed, he stepped forward and began, increasingly obviously to limp towards the starboard side of the ship and a point just out of sight of the bridge. He stopped by one of the larger aeroplanes, his uniform spotlit by the moonlight, and reached out as if to support himself on a wing strut. Then, as she held her breath, he bent and rubbed his leg.

He stood there for some minutes, his weight on one leg, shoulders slumped, staring out to sea. Then he straightened his shoulders and walked back to the hatch. By the time he reached it, his limp was no longer perceptible.

Afterwards, she could not articulate what it was about this brief scene that she had found comforting – whether it was the sea itself, her ability to carve out twenty minutes’ freedom unnoticed, or the small suggestion of humanity contained in the captain’s limp, a reminder of men’s fallibility, their capacity to conceal their hurt, to suffer – but as she came back down the stairs she had found herself somehow less conscious of the glances of those who passed, with a little of her confidence restored to her.