‘We’ll be back long before the storm,’ Robbie said. He pointed to a bench in the cockpit of the boat and busied himself around her, loosening and tightening lines and lowering a small outboard motor on the stern. He moved with quick competence; he’d done this a million times before.

He’d built this boat. He hadn’t said so, but she could feel Robbie in the curve of the bow, the blunt end of the stern. And the name, she realised with a pang, was obviously for his son, William. He’d spent hours making this boat and thinking of his son.

He did not touch her. No slight, almost accidental, meeting of hand and hand; no stolen caress as he went about the business of getting the boat ready to set off. He hadn’t kissed her on the dock, but she hadn’t expected him to. They were being discreet. But here they were almost alone. No one else was on the dock except for a pair of long-billed, shaggy grey and black birds perched on the roof of one of the fishing boats.

Every inch of her burned to touch him. Just thinking about him made her skin heat and her stomach feel queasy with desire. Her pulse quickened from being close to him. But he worked around her, almost studious in his avoidance. The only contact was the scent of bourbon that followed him like a shadow.

He’d suggested a sail instead of a hotel. And she’d thought of their first sail together. How he’d put his hand over hers on the tiller. Lightly kissed her ear as he taught her how to tighten the line, how to keep the wind in the sail, how to tack to change direction.

If Robbie touched her now, if he kissed her, she would at least be able to feel as if she had no choice. That she was being carried away by passion, that she had an excuse, however wrong, for her actions. Instead, she watched him start the motor and navigate the boat away from the dock, past some little scrubby islands out into open water.

Yesterday she had told her mother that she wanted to do a little bit of shopping for her and Christopher’s birthdays, which were both next month. They’d rented a car and gone down to Key West for the day, and were having dinner at a beachfront restaurant under a palm canopy. The surf washed the beach in a steady heartbeat and between waves little birds ran back and forth searching for prey. Emily had sat between Christopher and Polly, which at least hid the fact that both of them were conspicuously not looking at her. She could feel the hostility emanating from her sister. Polly’s movements were jerky and angry.

Christopher was hardly different at all from the way he normally was. Their conversation in the bathroom might as well have never happened. He had been as courteous as ever, as solicitous of her comfort; he’d been full of genial conversation with her family and when they’d gone to bed that night he had made sure to be in his side of the bed with his eyes closed and the light turned out before she emerged from the bathroom.

They often didn’t touch at night, but the gap between them had seemed very cold. Very large.

In the restaurant on Key West, the blazing orange of the sunset had reflected off her mother’s glasses. She wore a wide-brimmed hat and hadn’t tanned in the way both Polly and Emily had, but the colour of the sky gave her skin a tinge of pink. Charlotte Greaves had lifted her Mai Tai and said, ‘This is heaven. This is utter heaven. I’ve been so worried about you, Emily and Christopher. It’s such a relief to have you safe and happy with us.’

‘I’m just happy the whole family is together,’ her father had said. ‘Polly has been busy with work, and with the two of you away, it’s been lonely. I’m so very proud of you, all three of you.’

‘It’s all I’ve wanted,’ said her mother. ‘All five of us together. I just wish you could find someone to settle down with, Polly, who will make you as happy as Christopher makes Emily.’

And she had tried very hard not to look at Christopher and instead she had tried to look away at all the little hunting birds and caught Polly’s eye instead, and her sister was glaring at her with such anger that she had dropped her fork on the floor to give herself an excuse to hide her face under the table for a moment.

She had always been a role model for Polly. Her younger sister had always looked up to her, copied her, stolen her clothes, asked her advice, even though Polly was much more stylish and cool than Emily ever was, even though she was more fun-loving and less serious. She had been used to being Polly’s idol.

Seeing the contempt in her face made her feel sick. She barely touched her meal, and passed on dessert.

Robbie turned off the engine as soon as they were in open water and he began to unfurl the mainsail. ‘Can I help you?’ she asked him.

‘No, I can do it more quickly on my own.’

She watched him hoisting the sail and tightening the lines. The muscles in his arms flexing, his hands sure and strong. Two nights ago, he had touched her. He had breathed his secret sadness into her ear.

In the hotel room, she had known it was wrong but she had been too thrilled, too reckless to truly care. She had wanted him too much. But was wanting a good enough reason to ruin everything?

Surely this wanting would stop one day, and then what would she be left with?

Perhaps it had stopped for him already.

One moment the boat was clumsy, fragile, tossed by the waves. The next, the sail had caught the wind and it was powerful and sleek, moving so quickly, with the waves, that the movement was almost undetectable. The sea seemed to be motionless beneath them. And it was silent: nearly silent. Only a splash and a snapping of the sail.

This was like them. Caught up by the forces between them. Moving so fast that they hardly noticed that the rest of the world was stopping still.

‘Robbie,’ she said.

He was standing by the tiller, eyes on the horizon. When she spoke he looked at her at last. He sat down and held out his arm for her and she slid under it, nestling against his body.

‘Do you love me?’ he asked her.

She had not said it, not to him. Not since they had first parted, ten years ago.

She nodded.

‘Tell me. Say it. Please.’

‘I love you.’

His arm tightened around her, or maybe he was just trimming the sail. The scent of alcohol was stronger, here, close to him.

‘You’ve been drinking,’ she said.

‘I’m always drinking.’ He said it in a matter-of-fact voice. ‘It drowns out the taste of what I’ve done and what I am now. I’m not proud of it, but there it is. I’m just like Dad. Just like Dad, in almost every way. Except he liked planes, and I like boats.’

‘You don’t have to be like him,’ Emily said.

‘You’re a doctor. You know how powerful genetics are.’

‘Biology is just biology. It’s not destiny.’

‘Isn’t it?’

He pointed the boat out to sea, away from the shore.

‘And William is just like me,’ he said. ‘He looks like me, talks like me. He uses goddamn sandpaper like me.’

‘I wish I could meet him.’

‘I wish you could meet him. You’d like him. Right now he thinks I’m his hero.’

‘I’m sure you are.’

‘I’m not. I’m not anyone’s hero.’

‘Polly doesn’t like me much, either. Not since she found out about us.’

‘Tacking,’ he said, and she ducked as the boom swung around over her head to the other side of the boat. There was a moment where the boat wavered, unsure of where to go, but then it picked up the wind and they were moving swiftly again, towards land in the distance.