He began to descend the cast-iron stairwell, whistling to himself as he did so. She caught a snatch of it, that same military marching tune he’d been whistling before. What was the name of it again? She couldn’t remember. It didn’t matter.

She followed in his footsteps, hopping down the metal stairs, trying to keep up with him whilst also trying to remain as inconspicuous as possible.

When he reached the ground floor, he made his way towards the stairwell that led down to the basement, and at that point it occurred to her that he might be on his way to another rendezvous with Agata. But then again he might be up to something completely different. She wouldn’t know unless she followed him down there. So she did.

Once down in the basement, she hung further back, keeping behind the corners where possible to remain out of his line of sight should he suddenly turn around. There was just the sound of his soft whistling echoing back up the dingy corridors that told her that he was still somewhere up there ahead of her.

Then suddenly the whistling stopped.

Coming to a halt, she peeked cautiously around the next corner. The corridor was empty. He must have gone into one of the rooms. But which one and why?

She decided to wait where she was, reasoning that he would emerge eventually. If he doubled back up the corridor in her direction, she would have enough of a head-start to make it back up to the atrium before he reached her position.

It was perhaps three minutes that she had to wait there before the door to the workshop opened and Dylan emerged. He set off down the corridor in the opposite direction, away from her. The question now on her mind was whether his visit to the workshop had been part of a routine patrol or whether he’d gone in there for some other, possibly more sinister, reason.

She weighed up whether to continue following him or whether to check out the workshop. In the end, she decided on the workshop.

Waiting until he’d disappeared around the next corner, she stepped out and made her way to the workshop. She peered in through the wire-reinforced glass window. It didn’t look like there was anyone in there. She tried the door handle. The door opened. That was odd. She would have expected the room to have been locked when it wasn’t occupied. Maybe he’d forgotten to lock it. She pushed the door open and went in.

When in use, the workshop was probably one of the noisiest rooms in the prison, resounding with the racket of power tools drilling and grinding, but right now it couldn’t have been quieter. All the machinery sat dormant, switched off, and the only sound was the faint crunching of metal shavings beneath her feet as she paced slowly along the centre of the room between the rows of workbenches.

As she walked along, she looked around the room, taking in the racks of drills and woodworking tools hanging on the walls, the oxyacetylene tanks with their red and green rubber cables, the industrial lathe… the tiny reflections of herself in the chrome handles of the clamps on the benches.