‘I had to do everything for her, in the later stages,’ said Owen. ‘I had to get her up, wash her and dress her, take her to the toilet, wipe her, feed her, clean her teeth, then undress her and put her to bed again. What marriage involves that kind of intimacy between a man and a woman?’

Owen had begun to cry; the tears crawled over his skin like tiny slugs, slow and painful. ‘I’m sorry,’ he said. ‘I’m just glad she isn’t here now.’

Cooper looked away. He looked at the headstones in the graveyard, the yew trees and leaf-covered paths; he studied the village street, where a delivery van was parked outside the butcher’s shop, and he looked at the shadowed windows of the white house on the corner.

‘Owen?’ he said. ‘Shall I fetch that key for you?’

The interior of the church smelled of stone flagged floors that had recently been mopped clean. The light came from high in the walls, fragmented by the stained glass windows in a way that reminded Cooper of the cattle market at Edendale. The wooden pews were lined up just like narrow holding pens for worshippers waiting to be herded into the afterlife. He half-expected to see Abel Pilkington up there in the pulpit in his black suit, shouting out the prices, knocking down lost souls to the highest bidder.

‘You have to appreciate they’re treating this child pornography enquiry very seriously,’ said Cooper. ‘There was a little girl who ended up dead at the hands of two of these men. There may have been more we don’t know about.’

Owen nodded. ‘Of course, I regret what I’ve done. Somehow, I didn’t think of it as involving anyone else. I was still in my own private world, where it had always been just me and Mum, but now it was just me. And somehow – it was strange . . .’ Owen screwed his face up in an effort to explain the inexplicable. ‘But sometimes those little girls, Ben . . . I thought of them as if they were my mother. My own mother, as a child.’

Cooper lowered his eyes. There was nothing he could say, no platitudes that slipped into his mouth to meet the situation. His mind balked at being drawn into the dangerous, aberrant ideas that had appeared suddenly in front of him, like treacherous bogs across his path.

He felt guilty for stopping Owen. Being able to talk to someone would help him. But Cooper shouldn’t be talking to him about it at all. At any moment, Owen might make some damaging admission, and they would both be in an impossible position.

‘The cigarette stubs,’ said Cooper.

‘They’ve already asked me about those. Why do they matter?’