“You know exactly what it’s about. There’s no point in learning a bunch of useless stuff when I’m only going to forget it all later.”

Dad took a deep breath and I watched the muscles in his face soften. Beth’s fingers covered her lips. She looked sad.

Finally, Dad spoke, his voice quiet but firm. As though he thought if he spoke reasonably enough I would have to agree with him. “Saoirse, you don’t know what will happen. You have to keep living a normal life. Your mother did.”

Where did it get her? Locked up in an old people’s home and she doesn’t know her own last name. My phone vibrated again. I only half registered it. “She didn’t know this was going to happen. I know what the odds are. It changes things.”

Dad exchanged the most infinitesimally quick glance with Beth.

“Dad?” I suddenly knew what that glance meant. I knew it with my whole body because my legs started to feel weak. “Did she know?”

I asked because I wanted him to deny it.

“We should sit down. I’ll make a cup of tea,” Beth said.

I ignored her.

“Not early,” Dad said. “Not as young as you.”

Maybe he thought half the truth would satisfy me.

“When?” The word fell out like a stone.

Dad appeared to wrestle with himself and then finally one side won.

“Your mum was adopted, you know that,” he said. “But around the time we met, she was searching for her birth parents.”

I didn’t know that part. She’d never spoken much about them. Her adoptive parents were my grandparents and I never thought to ask her if she’d met her birth family. They never seemed very important to my mum, so they weren’t very important to me either.

“She found her mother, Joan. Or rather, she found a relative. A cousin. Joan had passed away already. The cousin, I don’t remember her name anymore, she told us Joan died young. Early-onset dementia. It progressed rapidly. We did some research and we knew then that there was a chance your mother would get it too.”

When Mum had told me I had a chance of getting it too, I had thought, doesn’t everyone have a chance? It was a while before I really understood what it meant. Mum and Dad had argued about it. A couple of years after they’d told me about her diagnosis, when I was about fifteen, I overheard them fighting. Mum thought I deserved to know. Dad thought it could wait. Mum said he’d wait forever if he could. Dad said maybe that wasn’t a bad idea. Mum said it wasn’t right for them to make that decision. Mum won.

“She knew before she had me that this would happen to her?”

I couldn’t believe she would do something so selfish.