‘There’s something – I have something – you must promise not to refuse it,’ she said. ‘I think – I can’t help but feel – I want you to have a small piece of me, something portable. A talisman, to protect you.’

I swallowed hard. She knew. Even without my saying a word she knew I would soon be gone. I was exactly one week away from vanishing. She was crying, and trying harder to cover it up than I was not to notice. I’d never told her about the contents of the bag in the garage, but it would only confirm what she already knew in her bones about Zac.

I tried to speak lightly. ‘Talisman, Milly? Are you catching your mum’s superstition?’

‘Maybe I am.’ She reached into the pocket of her dusty cardigan and pulled out a stone.

I blinked, and saw the stone as it was twenty years ago when I found it in the tide pools Milly and I had been exploring.

Then, it was shark-grey and prehistoric as a dinosaur, with a collection of small pits, the tiniest as if pricked by a pin, the largest as if by a pen’s nib. It was flat and smooth on the bottom, so it sat like a perfect paperweight, though several chalky scratches ran across it. The top was rounded gently. I pressed it against Milly’s palm and curved her fingers around it. ‘Paint this,’ I’d said.

She repeated my own gesture of all those years ago, putting the stone against my palm, curving my own fingers around it. ‘You remember it,’ she said. ‘I can see that you do.’

She’d enamelled it in a shimmering paint the colour of lapis lazuli. The flaws no longer showed. In her delicate strokes, as exact as the tiny brush of a portrait artist who specialises in miniatures, was a mother holding her baby. Their skin was bare, as if lit from within. The mother’s hair was a coating of amber, like mine, and matched her child’s.

‘Keep it with you,’ Milly said.

I kissed the stone. ‘Have you forgiven me for last week?’

‘Having a baby emergency is just about acceptable as an excuse. But sending my mother . . .’

I gulped, but nothing seemed to go down. She retrieved the water and I drank the rest.

‘I might forgive you someday,’ she said.

‘At least I have something to aim for.’ I rested my head on her shoulder.

‘I’m sorry I didn’t answer your calls,’ she said. ‘I couldn’t talk to anyone. I’d been crying and crying. People caring made it worse. I hate how pathetic I’ve been about that total prick. I should have picked up when I saw it was you.’

‘That’s okay. I know you. I know that’s how you work.’

She stroked my hair. ‘Baby girl is okay?’