‘Please don’t worry yourself,’ Annie said, going to her. ‘I’m happy to help.’ And as she said it she realized that she did feel in her element, helping like this. Not preaching – but doing and being useful.

She smiled down at Mrs Poole. The baby girl, Nellie, was on her back, a lock of blonde hair across her forehead, sweet-faced in the gloom.

‘I’ll come in tomorrow after work and see how you are. But now I really must get home – my uncle and aunt will be worried.’

‘Den,’ Lizzie said. ‘Take the lady back to her house. Chain Street, ain’t it?’

Outside it was quite cold and the fog had thickened so that they could barely see a yard in front of them. Each gas lamp offered a blurred aura of light, making the dark around it seem even denser. The damp air, full of smoke and other effluents, stung her nostrils and made her and the boy cough. Everyone in the streets seemed to be coughing and hawking as well.

Walking beside Den Poole was like being accompanied by a swaggering little man. Despite walking barefoot, he moved at astonishing speed, so that even Annie, who was nippy on her feet, had to make quite an effort to keep up, trusting that he knew where he was going. She prayed that one of her ankles would not turn on the cobbles or in some unseen hole as they crossed the road. But Den seemed to know every inch of the place, with all the certainty of a little dog. Thank heaven for him! How would she have found the way home through these invisible, sinister streets without this expert guide?

It was then she also realized that she was famished herself. She had no idea what the time was now. It felt like the middle of the night.

‘How old are you, Den?’ she panted, trying to be friendly as they scurried along.

‘Nine,’ he said, to her surprise. He was small for his age, she thought.

‘And your sisters?’

‘Ada and Ivy’re six. Dunno about Nellie. ’Er’s a babby.’

‘And what about your father?’ she said gently, somehow hoping to reach the young boy in him.

But it was like questioning a wall. He did not answer and she regretted asking. She had already wrung out of him the only words he uttered during their trot back to Chain Street. When they reached the end of the road, he stopped and pointed.

‘Thank you, Den,’ she said. ‘You’ve been very helpful.’

But he swung round instantly and disappeared into the murk and Annie could not help but think of a young rat, vanishing down a hole.

‘Where in heaven’s name have you been?’