They went past so quickly that I only glimpsed them and for a few seconds I was paralysed and couldn’t think what to do. Then I rushed after them, seeming to fly down the dimly lit slope of Catherine Street. A gaggle of children were shivering round the steps of the Catherine Arms, and as I passed there came a waft of warm, beer-fed air and a wave of noise from inside the cosily lit windows, voices singing above the talk. Otherwise the street was quiet.

They went right down to the bottom, towards Kemp’s, and I slowed down, frightened that they might turn and see me. At the corner they turned down into Vaughan Street and I hurried to keep them in view.

The two figures in front of me were walking side by side but not touching. I knew the man was Alec Kemp by the height, his walk. The woman beside him looked small and slight. Now and then they appeared to exchange a word, but they were brisk and purposeful. He seemed to be urging her on. Once I saw her stop and turn to look up at him, saying something. Alec appeared to speak softly, touching her shoulder for a second. I froze, seeing him glance back up the street. I should have kept walking, looked more normal. But he can’t have seen me. I saw he had his hat pulled down well over his face. They walked on.

As we neared Kemp’s, I realized the factory was still running. I had not given any thought to whether Kemp’s worked a night shift and had imagined him going to a place closed and deserted. Instead there were lights on, the front gates open, the hum of machines inside.

Surely to God he can’t be taking her in, I thought. Round the back, Jackie had said, but so far as I could see there was only the main gate. They were going past it. There must be another entrance behind.

Walking on the opposite side of the road from the factory, they skirted it and turned swiftly into the next street. I saw Alec putting his arm round behind her, urging her on.

Looks as if this is it, I thought. My heart was going like the clappers.

But when I turned the corner, they’d vanished. Damn and blast it! I stopped.

The street was a short one, linking Vaughan Street to the main road at the bottom. At a glance it appeared to present a uniform frontage of two-storey houses, but a short way down there was a break, a narrow alley barely wider than the entries to the back courts. The alley was pitch black and I didn’t much like the look of it but I didn’t see there was anywhere else they could have gone. I couldn’t miss this opportunity now. I stepped into the black slit between the houses.

The first part was very dark, hemmed in by the walls of the houses on each side. I couldn’t see the moon in the ribbon of sky, though I sensed the blackness thinning out ahead of me and becoming less intense. I felt my way along, moving my hands over the rough bricks, trying to tread absolutely silently. I heard a slight crunch as my foot pressed on broken glass. I stopped immediately and waited, taking in a deep breath and straining my ears to interpret the small sounds around me: the murmur of conversation from inside the houses, a distant rumble from Kemp’s and, surely, a faint voice from along the alley in front of me.