Christopher carried their coats and their smallest suitcase as they walked to the waiting bus. Even so, he touched her elbow as she stepped up into the vehicle, as if she needed steadying.

In less than an hour they would be meeting her family at the holiday villa they’d rented in Miami Beach. Emily hadn’t seen any of them for over a year; she hadn’t even spoken to them on the phone for weeks, as service was patchy in Bolivia at the best of times. But as the bus motored its way to the terminal, she wasn’t thinking about her father and her mother and Polly. She was thinking about Consuela Diaz.

Consuela Diaz was fourteen years old and a street child. She lived under a bridge in La Paz with a loose group of other orphans who lived by stealing, begging, scavenging and selling themselves. She had thick black hair that was tied tightly in plaits around her head. She was eight and a half months pregnant and her belly protruded from her skinny body.

She also had a suppurating foot, blackened and swollen, the result of a rat bite that had gone untreated.

When Consuela had come into Emily’s antenatal clinic early yesterday morning, Emily had seen Consuela’s smile first, and then her elaborately plaited hair, and then she had smelled the rot.

‘How much of her foot did you need to take?’ she asked Christopher, now, as they embarked from the bus. The terminal was air-conditioned and it chilled her skin.

‘Whose foot?’ Christopher was busy looking for the signs pointing them to passport control.

‘Consuela Diaz.’

‘The young girl with gangrene?’ He shook his head. ‘You saw how far advanced it was. We couldn’t risk the baby as well as her. I had to take it off mid-shin.’

Emily stopped walking on the polished floor. The other passengers streamed around and past them. ‘Mid-shin?’

She had held Consuela’s hand and told her: ‘I’m sending you to my husband, Mr Knight. He’s a good surgeon, and a good man; he’ll do everything for you that he can.’ And Consuela had nodded trustingly and her baby had kicked, and a beautiful smile had blossomed on her face. She had a gap between her two front teeth, which made her look even younger than she was.

‘Mid-shin?’ Emily repeated. ‘How is she going to survive, where she is, without half her leg? How is she going to cope with having a baby?’

‘With any luck, she’ll get a prosthesis. I spoke with Randall.’

‘I don’t think we should have left.’

Christopher put down their suitcase. He touched her chin, tilted up her head. ‘Darling. We did a lot of good, but our time there is over.’

‘We could have stayed. They’re not even getting a replacement OB/GYN for two months, at earliest.’

‘Our visas ran out. We can discuss going back. We have plenty of time to talk it over, once we go back to England. But this is our holiday, now. It’s time for us to relax. We’ve earned it.’

‘It’s difficult for me to think of us having a nice holiday in Florida while all of that is still going on back there without us to help.’

‘We can only do so much,’ he said, gently. ‘We have to think about ourselves, as well.’

She gazed at her husband’s kind, narrow face; his blue eyes behind his spectacles. His time had been worse than hers. Post-operative care in La Paz could be dire, and she knew that he often operated knowing that even if the surgery was a success, the patient might well die anyway. At least she had the compensation of delivering healthy babies.

He deserved a rest. He deserved a successful, lucrative career, and to make a name for himself as a surgeon. There was no reason why Christopher should have to share her dread at going back to England, to a normal life. An empty life.

‘I just can’t stop thinking about Consuela,’ she said.

‘I understand.’ He kissed her forehead and they continued on to passport control, where Christopher explained to the immigration official why they were in Miami, and had a polite few minutes’ chat about their work in Bolivia. In the luggage hall, Emily grabbed her own suitcase off the belt. It was light: hardly heavy enough to contain everything she’d lived with for two years. But then, all the important things she’d lived with in Bolivia couldn’t be carried in a bag.

Every day there had been a new emergency, a new problem, new lives. The clinic was over-used and under-staffed. For two years she had barely slept for more than four hours at a time. She worked closely with a number of Bolivian midwives but there were endless complications, and programmes to be developed for antenatal and postnatal care, for disseminating and educating about contraception when possible, for SDT testing and treatment. Christopher could help individual patients, but the changes she could help to make in this desperately poor area could help the next generation, and the one after that.

It had been inspirational and heartbreaking and exhilarating and depressing, and for two years she had barely had enough time to think about herself.

Whenever she thought about two weeks’ holiday with nothing to do, her mind shied away from it.

Christopher fetched a trolley and put their suitcases on it. He stowed their passports safely away in the breast pocket of his jacket, smoothed back his neat sandy hair. He smiled at her.

‘I can’t wait to get to the villa,’ he said. ‘I feel as if I could sleep for a week.’

Emily thought about Consuela Diaz, fourteen years old, pregnant, penniless, missing a family and half her leg, lying in the clinic, feeling her baby kicking beneath her hands.

Emily didn’t know if she was going to sleep at all, and if she did, what dreams would come.

She followed her husband through customs, out to the arrivals hall.

Robbie tucked his flask back in his pocket and popped a Wint O Green Life Saver. If his breath smelled of Jim Beam he wouldn’t have five minutes of peace before they got home and he could escape to his shed. And he didn’t want to have to escape; he wanted to play Hot Wheels with William and tuck him into bed. While William and Marie had been gone he’d set up the kid’s bedroom with an elaborate track for the cars to go on, hills and curves and loops.

Marie was going to go crazy, of course. She’d been gone a week and Bob had made another mess she would have to clean up. But he couldn’t resist making the track bigger and bigger until it reached from the bed to the door and covered nearly the entire room in an orange plastic tangle. And William wouldn’t see it as a mess. He’d see it as heaven: something that his daddy had magically created for him.

Robbie couldn’t wait to see his face. The two of them would spend a long, happy time zooming the cars around, racing, adjusting the track so the cars could go faster. Two peas in a pod, Marie would say, in a disapproving tone, and Robbie would try not to think about the times that his own mother had said exactly the same thing about him and his father.

He pulled out the flask and unscrewed it before he remembered his resolution not to smell of bourbon, and put it back into his pocket. He lit a cigarette instead.

Their plane should have arrived already, but the lady at the counter had said it had been delayed in Chicago by bad weather. So he stood at the arrivals gate with the crowd of people waiting, and watched the people coming through the doors. All the little dramas going on around him, with people flying from all over the world and arriving home. A family came through, mother and father and a toddler and a baby, and the elderly Latino couple standing next to him cried out in joy. The toddler wobbled over to them to be scooped up and fussed over. A slender young man with an Afro emerged, looking anxious, until he spotted a tall young woman in the crowd and the two of them ran to each other and hugged so hard they looked as if they were going to meld together. A grey-haired woman in a flowing caftan wafted through the door and the expression on her face when she scanned the crowd was almost angry. It set into grim resolution as she approached another grey-haired woman, in a pants suit, and the two of them leaned forward to kiss each other on the cheek with the minimal possible contact.