The ‘nightly rounds’ she referred to were a real thing. Sister Cassie spent the best part of each day scavenging what scant supplies she could – food, drink, cigarettes, money – and despite holding some back in order to feed her own habit, was often able to make a nightly circuit of the doorways, sewers and underpasses where so many of Crowley’s homeless bedded down, doling out whatever she could to the most needy, or sometimes simply offering company and comfort.

‘But the first point I made still stands,’ Lucy said. ‘Edna Davis, Ronald Burke and Fred Holborn … they might just have wandered off.’

Sister Cassie shook her head.

‘Look,’ Lucy said, ‘they may have been fixtures in Crowley for years, but there’s nothing to keep them here.’

‘I know these people well, child. None of them have anywhere else to go.’

‘What do the others think?’ Lucy asked. ‘I mean, the rest of your community.’

‘They’re as worried and bemused as I am.’

‘So why haven’t they come forward? You say Ronald Burke vanished two or three weeks ago.’

‘My child … they will not come into a police station.’

‘Why not?’

‘They don’t trust you. And why should they? One young lady I see on my regular rounds … she was raped by a gang of men some nine months ago. Not just raped, sodomised too. It was a terrible attack and I know, because I’m the one who cared for her afterwards and persuaded her to go to the police station.’

‘I don’t remember this,’ Lucy said.

‘It wasn’t here at Robber’s Row, it was at Cotehill Crescent.’

‘Okay, and …?’

‘Well …’ Sister Cassie sighed again. ‘It’s a sad tale already, but it gets sadder still. While the police ladies were helping her undress for examination by the nurse, they found certain substances. As such, this young lady herself was questioned. It made her feel very uncomfortable … as if she wasn’t already uncomfortable enough.’

‘I do remember that one, actually,’ Lucy said. ‘That young lady had quite a bit of heroin on her, and several uncapped needles, all of which she failed to mention. As a result, one of the policewomen assisting got her finger pricked and had to go through all kinds of health checks afterwards. Are you surprised they got cross with her?’

‘It doesn’t matter. They were searching for evidence that might have incriminated the young lady’s attacker, and they ended up making a fuss about evidence which might well have incriminated the young lady herself … and for something completely unconnected with the original complaint. So, you see, child, my community, as you call it, is not very keen on your community.’

Unconnected with the original complaint …

Lucy thought about that, wondering why it seemed meaningful.

And then the penny dropped.

‘Is everything all right?’ Sister Cassie said, noting Lucy’s gradual change of expression.