‘Hey, sit,’ said a lad in his teens, leaping to his feet and smiling. Had he picked up on her breathing technique – those restless, twitching feelings?

I’m twenty-nine, not ninety, she almost said. But the truth was she was relieved. She had been on her feet all day taking pictures around Tower Bridge for an article she was working on, and that horrid heat was basting the backs of her knees, the curves of her elbows, making them sweat.

‘Thanks,’ she said, and thumped down in the vacated seat, realising instantly why the bloke had moved. A fish-sandwich muncher was sitting right next to her.

Her phone rang in her canvas bag, and she pulled it out to see Jack’s face beaming from the screen.

‘Hey, you,’ she said, pinning the phone to her ear.

‘You OK?’

‘Yeah, just delayed. Train’s rammed.’ It jolted forward and headed on its way. ‘Ooh, we’re moving, thank the Lord. Should be home in about an hour.’

‘Great. I’m cooking teriyaki chicken. Mary Berry style.’

She laughed, scooping her hair behind her ears. ‘Lovely. I’ll pick up wine.’

The line went dead as the train rumbled through a tunnel, and Isla slipped her phone in her bag, and took out her camera. She flicked through her photos. She would add one or two to Facebook later, and mention her long day in London.

Your life is so perfect, Millie had written on Isla’s status a few months back, when she’d updated that she and Jack were back from France and she was closer to finishing her book. It had been an odd thing for Millie to say. Her sister knew Isla’s history better than anyone. How could she think Isla’s life was perfect, when she’d seen her at her most desperate? Felt the cruel slap of Isla’s anger?

Eyes closed, Isla drifted into thoughts of Canada. She was going for a month. Alone. Canada. The place she would have gone to after Australia if life hadn’t forced a sharp change of direction. Going abroad without Jack wouldn’t be easy. But then he couldn’t keep carrying her. She had to face it alone. And it would be the perfect escape from the pending appeal.

With a squeal of brakes, the train pulled in to Finsbury Park, and fish-sandwich man grunted, far too close to Isla’s ear, that it was his stop. She moved so he could pass, and shuffled into the window seat.

Through the glass, she watched overheated people pour onto the platform, and her eyes drifted from a woman with a crying, red-faced toddler, to a teenage boy slathering sun cream onto his bare shoulders.

‘Isla?’ Someone had sat down next to her, his aftershave too strong.