The tour had gone well, so far. The magic of Tuscany – with its soft light and purple hills, its ancient culture amid such quiet beauty – always seemed to cast a spell over her charges. She felt she was seeing their best selves. One American complained about the lack of handrails on the steep streets of Siena, and she lost some of her group for half an hour during a climate-change protest in Pisa, but otherwise the only problem, with so many older travellers, was the searing heat.

There had been no sign of Jared. He must have meant what he said, Connie thought, as she lay awake night after night. She was ashamed to admit how dismayed she felt. But she knew that now she needed to shut down every thought relating to her time with him. Allow the images to fade, box up the bewildering pleasure she’d experienced in his company and lock it into the attic of her mind where, in years to come, she might bring it out and smile guiltily at the memory.

Life would gradually return to normal. It’s what I want, she told herself repeatedly. Her husband was irritating her at the moment but, then, whose spouse didn’t? She just had to be patient. These exhortations, however, did little good. Through the hot Tuscan nights her faithless body still ached to be lying in Jared’s arms again. But he didn’t come.

By the time Connie was lying sweating in her hotel bed in Turin – their stopover on the journey home – she knew this was more serious than a summer cold. Decongestants and copious quantities of paracetamol from the medicine chest she always carried on tour had staved off the worst during the remaining days in Florence, allowing her to function, just about. But she’d developed a nasty cough and her chest hurt, her head throbbing constantly. A couple of passengers commented that she didn’t seem well, but she brushed off their concern with a smile. She’d purchased hardcore cough mixture from a sympathetic Italian pharmacist near their Florence hotel; he’d also suggested she see a doctor – which she stubbornly felt she didn’t need – but the stuff made her drowsy and increasingly didn’t seem to touch the problem.

Connie made it to St Pancras in a feverish haze, holding on by her fingernails until she’d said goodbye to all her passengers and seen them off on their various journeys home. By now she barely knew who they were, their faces swimming in and out of her vision in a baffling way over which she seemed to have no control. She prayed she wasn’t saying weird or stupid things. But apart from one of her clients who said in farewell, ‘You should get that chest seen to, Connie,’ no one had seemed to notice that anything was wrong.