She placed the mug on a coaster. Their wedding album had been removed from its drawer and lay open on a photograph of the two of them at their engagement party, as if someone had been poring over it. The knot in her stomach tightened. She looked so young. Vulnerable, even. Her hair was much lighter and she was too thin. Her resemblance to Shannon was striking. It gave her a jolt to remember herself like that.

Had Edward been looking at those pictures? Or Honor, perhaps. And if so, why? With the Hilltop House murders back in the news, it felt too uncomfortably close to home to be coincidence. Was it possible her husband had overheard her telephone conversation with Eliza, her only real connection to the past? But surely he would have spoken up if he’d had the slightest inkling who she was.

Either way, her likeness to her older sister upset her, even if it hadn’t survived into their thirties. When the snow had cleared and she was alone, she would get rid of that photograph. All the wedding photographs, if necessary. She smoothed out the tissue paper, shut the album carefully and left without a word.

The rest of the afternoon crawled by. Honor had shut herself away in her bedroom. ‘Homework, Mum.’ Edward had not come out of the study. Catherine sat alone in the sitting room, watching the sky darken and the snow fall, butterflies brushing their wings against her insides. Unsettled. That was the word. As if her life was a pool of water and its surface had been disturbed.

As a general rule, she didn’t watch television during the day, but this was not an ordinary day. The snow lay thickly across the garden. Winter was everywhere, the air taut with it. She could taste it when she opened the back door to throw crumbs to the birds, and smell it in the woodsmoke, and feel it in the tiled floor of their north-facing kitchen. And she was in need of distraction.

An auction of antiques and collectibles. A teatime quiz show. The opening beats of the BBC’s News at Six.

Her hand hovered over the remote control. She should change the channel. But a masochistic need compelled her to watch on.

The slaughter of her parents had graduated into the lead news item of the day.

A man who seemed familiar was walking briskly along the pavement of a smart London street, a look of concentrated nonchalance on his face. He held a briefcase in one hand and snowflakes were settling on the shoulders of his double-breasted woollen overcoat.

Camera crews and journalists surged towards him in a fluid pack, shouting questions, demanding answers.

‘Mr Heathcote, do you really believe the Angel of Death should have been hanged?’

‘What do you say to accusations of hypocrisy, Lord Chancellor?’

‘Are you planning to resign, Justice Secretary?’