Sitting opposite me in a hotel room in the town where she was brought up, Katie Walmsley quietly described her childhood. Her parents were splitting up, a priest suggested to her dad that the best place for her would be a children's home for girls. The nuns would keep her safe and well.
"I held on to my daddy's trousers," at the door of the big, imposing building, she said. The nuns pulled her in, and within ten minutes she was sitting with her sister in a bath mixed with jeyes fluid (a toxic industrial detergent people normally use nowadays to get congealed fat out of drains).
Head partly shaved to look like a boy. The terror in the eyes of her sister. These things have been seared into her consciousness.
Katie will give evidence to Britain's biggest ever inquiry into systematic abuse next week. She will tell the inquiry what she told us here that the congealed pig fat - slops, she called it - was scooped up in a tablespoon by the nun when she vomited it up and she was forced to eat it again.
That the nuns made her clean the excrement from toilet bowls with her bare hands, and pick bits off the walls with her fingernails.
That she was punished for wetting the bed in fear, and grew up believing bed wetting had led to her parents' separation.
That she was told she didn't deserve a doll for Christmas because she had been bad.
That the priest told her she didn't need to pray because she had been good in God's eyes. Instead he "took me round the back", made her go down on her knees between his legs and by the time she was 12 he had done worse still to her.
Our conversation took place in Derry, to use the name Katie and other Catholics have for it. It's Londonderry if you're a Protestant, and in the still complicated Northern Ireland you have to use both to avoid being seen to be partial.
What's striking about this inquiry is not just the testimony of people like Katie, but that this abuse was taking place not in Catholic Ireland, where politicians and society all turned their heads away, but in the UK, in a small town run for decades by Protestant minority political leaders.
How could nobody know?
During the Troubles, the low grade civil war between Britain and the Irish Republican movement, this town was a focal point for the conflict. One argument might be that security was the only story, and nobody had their eye on the nuns.
But now many we spoke to think something else was going on. Jon McCourt, now a peace campaigner but who was himself a 'home boy', abused in the town's boys' home, is adamant the authorities knew and didn't want to act.
At the time, he explained, housing policy in Derry/Londonderry was linked to having a vote.
The more Catholics who got state housing, the more votes they would have, and that could have upset the political balance of power in the town. The more boys and girls in homes for years and years, the fewer houses needed for Catholic families.
Well-known journalist Eamon McCann goes further. He believes the Catholic Church was only too keen to work with the Protestant political leadership to take poor kids off the streets and put them in homes.
Why? Because it kept them off the streets, away from the hands of Republican dissidents, and out of sight.
The church also organised for children to be exported to other countries like Australia and Canada, where the church was extending its reach. Many children say they got abused there too, having been told on the boat they now had a different name and no family. 'Social fascism,' McCann calls it.
Most of the people who might have been involved in organising all this are dead, but some are not. The survivors say they know where one or two of the nuns and priests are.
The inquiry does have the power to pass on anything new to the police. It's also worth pointing out that as it goes on, the inquiry will hear about abuse in non-Catholic homes around the north.
But here in divided Derry/Londonderry, what's emerging isn't only a story of shocking abuse. It's the allegation of the Catholic Church taking children in a way which suited perfectly the interests of the pro-British, Protestant political elite which is so outrageous and tragic.
Hundreds of vulnerable kids sold down the river, betrayed by both sides.