‘And you were the only one who knew who they really were?’

Ruth nods. ‘Mary never told a soul. Oh, now, she built a good life for the two of them; they had friends, they had a house, it was all very normal, don’t worry.’

‘And they had you.’

‘Yes.’

‘Where did they live?’

‘I thought she should go down the country, live in the middle of nowhere, away from prying eyes. But Mary’s from California, and she always said cities are the best place to be anonymous. The easiest place to hide.’

‘So, they stayed here in Dublin?’

‘They did. I thought she was mad, but she proved me wrong. To begin with, they moved to a convent in North Dublin; an order I knew from my time teaching. They lived with the nuns for a few years, keeping their heads down, then they lived in Marino, not far from the city centre. In a huge but perfectly nice, normal housing estate where people are friendly but leave each other in peace. Mary said she was a “single mom” who’d split from her husband in Canada and was starting a new life here. Nobody ever questioned it. Lizzie was older by then; her hair had grown longer and much darker, light brown instead of blonde. I still thought people would recognize her, but over time I began to relax.’

‘But what about the media? The police?’

‘None of the journalists ever found her – the years in the convent were enough to break all links between Mary Murphy and Mary-Ann Holborn. Word went around that she’d moved back to the States, and over time, that became the accepted story.’

‘But surely the police had to stay in touch with her?’

‘They did. They gave her updates every now and then, or rather, news that there was no news. But she always called to the station to meet with them. They never saw her house, never saw Lizzie. They believed Lily had drowned and that Mary was a grieving mother – they had no reason to think she’d taken her own child.’

‘So you were the only one who knew.’

‘Yes, and during the early years, I was terrified they’d be caught. But they moved house twice after they left the convent, and by the time Lizzie started secondary school out in Swords, even I had to admit nobody would ever guess that tall, athletic, cheeky, dark-haired Liz Holborn was really little blonde Lily Murphy.’ Ruth smiles and there’s such fondness in it, I find I’m welling up.

‘Little blonde Lily Murphy, missing, presumed drowned.’ The words are out of my mouth before I can stop myself, and I regret them immediately.

‘Yes. Well. It wasn’t perfect. I can’t pretend I was comfortable knowing people were still searching, gardaí wasting time. But we couldn’t risk telling anyone. Mary might have gone to jail. I could have handled prison, I had no children or husband to worry about. But she needed to be here for Lizzie. So we stuck to the plan.’