She walked on, increasingly puzzled, coming to a derelict railway line so tangled in thorns that she half tripped over it. She followed this into a canyon between the soaring outlines of the two main structures. Concrete platforms now stood on either side, and Lucy climbed onto the one on her left. It was scattered with bottles, cans, food cartons and wastepaper – yet more indications that folk had been living here and probably still were. She glanced behind continually as she ventured along it, still seeing no one, though when she looked left through the various apertures into the warehouse proper – tall, glassless window frames, or even larger gaps where loading-bay doors stood partly open – it was easy to imagine furtive movement in the darkness. She was tempted to shout, to simply call Sister Cassie by her name, but Lucy didn’t think she’d like the way her voice would echo through the labyrinthine concrete.

She pressed on, holding back from switching on her Maglite, as that would indicate that she might be worth attacking after all. Besides, dim but adequate starlight from the narrow strip of sky above showed that she was approaching the end of the platform. A crumbling mass of half-collapsed brickwork was all that remained of the wall in front of her. On her right, down in the pit, she saw railway buffers peeking through the dense, rancid foliage. On her left, an entrance gaped, a corridor of sorts, which appeared to lead into the very guts of the warehouse. She glanced back along the platform to her rear, just to ensure that hostile forces weren’t encroaching from behind.

It wasn’t easy to be sure. Beyond a couple of dozen yards, the dimness obscured much, allowing for optical illusions. What appeared to be someone crawling towards her on all fours, and freezing on the spot when she looked, gradually resolved itself into a crumpled heap of cardboard.

She glanced back into the passage on her left. If it had ever had a door, it was long gone, but it seemed to offer a direct thoroughfare from one side of the building to the other. That was the obvious way to go next, though Lucy wasn’t convinced that it would be sensible. It wasn’t as if she was anticipating trouble – if so, she’d have called for support. The problem here seemed to be that the place was empty. For all that this dark, decayed environment was menacing, she was sure that no one back at the nick would think any less of her if she delayed this thing until daylight tomorrow.