We rode on, side by side. “Gertrude, that was a dreadful murder. I hope I haven’t made it difficult for you, joining in that procession yesterday?”

“You’re investigating again, aren’t you?”

I dodged the question. “I’m tempted to investigate, but no one has asked me to.” Given that we were talking about Mrs. Farrar’s death, I was telling no lie.

“You must believe Stephen Walmsley is innocent or you wouldn’t have joined the march.”

“He has a huge amount of support from people who believe he didn’t do it.”

“It was utterly sickening, Kate, what he did to that poor woman. It was him all right. The police have the killer. Walmsley had blood on his hands.”

Just for a moment, I let myself imagine that Stephen was guilty, that she was right and I was wrong.

Gertrude had no doubts. “We don’t know what sort of wicked strain Stephen inherited. No one knows who his father was.”

“What about his mother?”

“Her husband threw her out, and then took her back. They moved away, to avoid the shame. As soon as Stephen was old enough, Benjie gave him a job at the pit. He’s very generous like that. And this is how we’re repaid. Murder on our own doorstep.”

“I hope he’ll get a fair trial, Gertrude.”

“Of course he will. Everyone does. This is England. We bend over backwards to be fair to rascals. I know that you thought I was being picky, not wanting a child whose history is unknown. There is such a thing as bad blood.”

We rode on.

The Miners’ Welfare Institute stood at a little distance from the school. I dismounted and took photographs of both buildings. It was one of those standard-built schools, put up to meet the requirements of the 1870 Education Act.

“I expect you want to see the mill, too.”

I had not thought of that, having seen enough mills to know what they are like, but I said yes.

From the way Gertrude said, “Oh come on then. I suppose you might as well,” I realised I had given the wrong answer.

“What’s up, Gertrude?”

“I had a telephone call just before we left. It was for Benjie but of course he’s off on one of his jaunts. We had to cut the workers’ hours and halve pay.”

“I’m sorry to hear that.”

“We have no choice. The over-lookers have accepted the inevitable, but the women are objecting. With their impeccable logic, they have walked out. I didn’t want to burden you with our troubles.”

“Do you need to talk to them?”

She sighed. “I should. The foreman seems to think I might be able to persuade the women to listen.”

The upshot was that we left the horses by the mill gates and went into the yard.