Romy glanced quickly at the post, which held nothing of any interest except one handwritten letter, addressed to ‘Mrs Claire’. The envelope was cream and good quality, her name and address handwritten in italics and black ink, a script she did not recognize. It was addressed to Michael’s chambers, ‘Private. Please Forward’ in the top left-hand corner, Wendy’s neat redirection sticker sitting beside the crossed-out black ink.

Intrigued, but with no time to waste – she was due in Barnes, at the London Wetlands Centre, where she volunteered one day a week, taking groups of school children around the park – she stuffed the letter into her handbag, dumped the rest of the mail on the ledge above the hall radiator, then hurried down the stairs and out into the gusty autumn day, pulling the hood of her parka over her head to prevent the drizzle playing havoc with her already chaotic curls.

It wasn’t until Romy was seated on the Tube, trundling along the District Line to Hammersmith, that she remembered the letter and took it out of her bag. At first she couldn’t understand what she was reading. She stared at the words, but they made no sense. She glanced furtively at the man sitting next to her – the contents seemed to be shouting at her, and she worried he could somehow hear too. But he was deep in the yellowing pages of a John Updike novel.

The carefully scripted words swam before her eyes as she read and reread the text. The woman – as she would be now – said it was ‘too small a world’ to identify herself, whatever that meant. Is she implying she knows us? she wondered. Stations came and went, passengers ebbing and flowing around her. The sun pierced the grimy window in a blinding shaft as the train came overground and Romy shook her head in shock, quickly followed by bewilderment. There must be some mistake, she thought. She can’t be talking about Michael. Romy’s husband.

But it was clear that she was. She had seen him on the television, named him specifically. Romy’s thoughts were a jumble as she tried to work out what it meant, who this woman might be. She was so explicit. The sofa in Michael’s office; Wendy’s beige cardigan. Her stomach twisted. For one horrible split second she couldn’t prevent the thought that the letter might be telling the truth: that her husband might actually have done such an appalling thing.

Then she pictured Michael – her intense, charismatic, workaholic star of a husband. His dark eyes were always sharp with intelligence, but also vulnerable and fiercely honest.