It’s late. Friday night. Cathy’s seeking refuge at her parents’ house. She wants to call 999. To falsely confess. To end the nightmare for all of them.

She came here instead of doing that.

Tom has called her twice, but she didn’t answer either time.

‘You’re all right, aren’t you?’ Owen says. Cathy turns to him in surprise in the darkness.

‘I’m fine,’ she says.

‘Well,’ Owen says, and then he reaches out to clasp her shoulder. ‘You seem down.’

She looks at him. How could she tell him? She thinks of the days, weeks and months after Rosie’s death. They never, ever mentioned Cathy’s role in it. Cathy was waiting for them to. They came home from the hospital without Rosie. They arranged the funeral. The topic was dropped, a radioactive family secret they unsuccessfully tried to bury even though it throbbed underneath the earth. And their behaviour towards Cathy changed, cooled, became resentful, in some ways. She was struck by the distinct feeling that her mother was acting around her.

Three months after Rosie’s death, it was Cathy’s birthday, and they got her a card and a voucher. That was it. Cathy still has the voucher. Unspent, kept forever, a gruesome memento of what happens when you make a mistake.

‘Well, you know,’ she whispers to her father now, desperately wanting to ask, suddenly, in the aftermath of her sister’s mistake, about her own. He holds her gaze for a few seconds, saying nothing. ‘Do you think sometimes good people just – pure and simple – mess up?’ she says in a low voice.

‘Of course they do.’ His eyes seem to harden in the night air in front of her, and she has a sudden feeling that she is crossing some point of no return that she isn’t ready for. ‘Why?’ he asks.

‘Just asking,’ she says softly, through tears. She’s sure she sees his eyes shining too.

‘Did something happen on the holiday?’ he asks. All around them, Cathy can hear the drip of rainwater falling off the plants. She’s surprised by the direct question. He is usually repressed, usually feels it would be better to say nothing than something, no matter what. She looks up at him.

‘This and that.’

He would be one of the last people she would tell, she thinks sorrowfully. He wasn’t there for her during that most crucial part of her life, and now she is damaged forever.

‘Well, I hope nothing serious.’ He holds her gaze for a second and she wonders if he knows. He can’t. But perhaps some parents can just sense certain things.

‘Since you’ve come back you don’t seem as – as close. And – you know. It’s a tough week for us all. I thought I’d see if you were all right.’

Cathy almost takes a step back. It’s Rosie’s birthday. Cathy has been over her late sister’s features so much that she can hardly recall them now, needs photographs, all of which she’s already seen. She can’t imagine the adult she would have become. Perhaps she would have been Cathy’s ally, perhaps the triangle would have been a square instead.