He widened his eyes in such a puppy-dog penitent expression that she couldn’t help but laugh.

‘Yes,’ she said. ‘But that last Coke is mine.’

And she took it.

They emerged from the station in Lowestoft to a deserted street in strangely muted light. Grey clouds rolled between the buildings; Emily instinctively breathed in but smelled nothing, and it still took a moment or two for her to realise that it was fog, not smoke.

‘It’ll burn off within a couple of hours,’ said Robbie, taking her hand.

‘And I’m supposed to believe your weather predictions now?’ But she clung to his hand; the town felt empty, as if they were the only two people in it. Their footsteps were muted and Emily felt a film of damp settling on her face, her clothes, her hair; her eyelashes felt heavy and moist. ‘It’s like being inside a cloud,’ she said.

‘I should really say something about you being an angel at this point, but I’m scared you’re getting tired of my lines.’

‘They’re very well practised.’

‘Well, then you won’t be surprised when I say I’d like to introduce you to a lady that I’ve been spending a lot of time with.’

She shot him a look but he was smiling. He’d been so sure of himself, from the moment she’d met him. She wasn’t usually attracted to arrogance; quite the opposite. And the thing about his lines was that even though she knew they couldn’t be, they sounded totally sincere.

The buildings opened out to an esplanade, presumably fronting the sea, but all Emily could see was a wall of grey, with fog billowing in. She shivered and Robbie took off his jacket and put it over her shoulders.

He led her down a set of steps to a wooden walkway. The scent of the sea was stronger here: she could see greyish-green water lapping at the walkway, and sense large ghostly shapes around them. Every now and then, the splash of a wave or the clink of metal against metal.

‘She’s here,’ he said, and as he said it the boat loomed out of the fog, suddenly solid and real.

It had a red hull, two masts; it was wide and long with a spotlessly clean deck and hundreds of incomprehensible ropes everywhere. Robbie put his hand on the side of it, as if he were fond. ‘Emily Greaves, meet Nora Mae,’ he said. ‘This is the lady I was telling you about.’

‘The boat?’

‘She’s a sixty-foot ketch, made in Annapolis, Maryland about six years ago. I’ve known her all her life.’ He patted the hull again. ‘I put this paint on myself.’

‘You built this boat?’

‘Parts of her. We’re very fond of each other.’

She tried to imagine building something as big and intricate as a boat by hand, and couldn’t. ‘Do you own it?’

‘Her,’ corrected Robbie. ‘No, she’s owned by a oil magnate from Texas called Bud Walker. Before that, she was owned by a New York banker called Chad Lund.’

‘But you sail her? This Texas owner hires you to sail his boat for him?’

‘He pays me to crew sometimes, yes. When he’s on the Chesapeake, which is about four weekends a summer. Bud can sail, just about, but he likes to have yacht parties more than he likes to do any of the actual work on board. I look after her when he’s not around, and do the overwintering work on her, and this year he wants to spend the summer in Italy, so I’m sailing her to the Med.’

‘By yourself?’

‘We’re a crew of three. Come and meet them.’ He led her to the back of the boat, where the hull dipped enough so that he could climb on. He put down his hand to help her up.

It felt somehow different from being on land. The water was calm in the marina, and the movement of the craft was very subtle, but the boat felt alive.

‘I’ve never been on a boat before.’

‘You were on a punt two days ago.’

‘I mean a real boat, a big boat.’ She peered upwards at the masts, which were tall enough to disappear in the fog. An undetectable breeze made the ropes flap slightly. ‘What do you even do with all of these ropes? There are so many of them.’

‘Not so many, when you know what they’re for.’

‘I can’t imagine knowing.’

‘Don’t you know all the names of all the veins in a human body? It’s easier than that.’

‘Not to me.’ Gazing up at the ropes, she felt for the first time exactly how much of a stranger Robbie was. Not just his past, or his motivations: there was this whole world of knowledge and competence inside his head – knowledge about a thing that she’d never even given any thought to.

A head popped up through the door leading below deck. ‘Thought I heard you up here, Bob. I was expecting you last night.’

The man wore a blue baseball cap with a red B on it and a dirty grey shirt. He was older than Robbie, his face was weather-beaten and sunburned. His accent was similar to Robbie’s, but with softer r’s, flatter vowels, a slower way of speaking. He regarded Emily with distinct surprise.

‘Something happened. Emily, this is Dennis, my first mate.’

‘You’re the first mate. I’ve been the captain since you didn’t come back last night.’

‘Dennis, this is Emily.’

He stretched his hand up for her to shake. His skin was rough and calloused, like tree bark. ‘You any good at cooking, Emily?’

‘Don’t be a chauvinist,’ said Robbie. ‘She’s going to be a doctor.’

‘I can also cook,’ said Emily.

‘If you’re on board, you have to be useful. I have a dozen eggs to use up before Art gets back with the supplies and Bob’s omelettes are like rubber.’ Dennis went back down below.

‘You don’t have to cook,’ Robbie told her.

‘I don’t mind. And I’m hungry. We haven’t had anything proper to eat since yesterday.’ She followed Dennis down the hatch. The stairs were more like a ladder; she had to hold on tight to the handholds not to slip. She couldn’t imagine what it would be like at sea, with the boat rolling all over the place.

The ladder led down into the kitchen area, which had cabinets, a cooker, a sink. Beyond it there was a seating area, with benches and a table, lamps, a bookshelf. All of it gleamed with polished teak and brass; the seats were upholstered in leather. Between the portholes, or whatever the windows were called, there were actual oil paintings of horses on the walls. Compared to her Spartan room in college it was a mansion. ‘Wow,’ she said.

‘Bud had the whole thing refitted when he bought it,’ Robbie told her, swinging down the ladder with ease. ‘It’s a nice home for a few months. Nicer than my actual home. Here, I’ll show you around.’

He put his arm around her waist and gave her a tour of the boat: the radio, sonar and charts hidden in a teak cabinet set into the wall; the way the dining table pulled out to seat at least ten; the compact bathroom with a toilet, sink and shower; the cabins, with beds neatly made and a sink in each room. There was no clutter anywhere. You would hardly know that three men had lived on this boat for weeks.

‘Which one is your room?’ she asked him.

‘This one. The aft cabin.’

She went further into it, looking for a sign of Robbie, something to tell her more about him. He’d slept in this bed while he sailed across the entire Atlantic ocean; he must have dreamed in it.