It was from beneath the heap of clothes that the noise came, monotonous and inhuman, a low, desperate wailing. When he moved towards the bed, the mound stirred and the keening turned to a fearful whimper. Cooper knew that the crisis was over, for now. But this had been the worst so far, no doubt about it. The evidence was all around him.

He leaned closer to a coat with an imitation fur collar, but was careful not to touch the bed, for fear of sparking off a violent reaction. The coat was drenched in a familiar scent that brought a painful lump to his throat. A white hand was visible briefly as it clutched for a sleeve and the edge of a skirt to pull them closer for concealment. The fingers withdrew again into the darkness like a crab retreating into its shell. The whimpering stopped.

‘It was the Devil,’ said a small voice from deep in the pile of clothes. ‘The Devil made me do it.’

The mingled odours of stale scent, sweat and excrement and urine made Cooper feel he was about to be sick. He swallowed and forced himself to keep his voice steady.

‘The Devil’s gone away. You can come out now, Mum. The Devil’s gone away.’

When Fry went back in to interview Martin Rourke for a second time, he’d been allowed to consult a lawyer. She was expecting a string of ‘no comments’, and a frustrating end to her trip to Dublin. But maybe things were different here.

‘Of course I remember her,’ said Rourke straight away. ‘I want to be honest with you.’

‘Remember who?’

‘Nadezda, the Slovak. She couldn’t resist trying out the crank herself. Stupid bitch. It made her careless. She was bound to kill herself sooner or later.’

‘Kill herself? You’re suggesting that Nadezda Halak died in an accident?’

‘That’s exactly what happened. It was accidental death, brought on by her own carelessness. That would be a factor, all right.’

Fry glanced at Lenaghan, who gave her a nod to go ahead.

‘Mr Rourke, tell us exactly what happened, in your own words.’

‘Well, there’s nothing much to tell. There was an explosion in the shed one day. None of us knew the chemicals were so dangerous. Nada had been standing closest to the equipment when it blew up.’

‘Nada is …?’

‘The woman you said. Halak. Nada is what we called her, for short.’

‘And she was killed by the explosion?’

‘Dead as you like. It was lucky she was the only one so near. There were other folk about, but they only got a few cuts, one or two acid burns. Nothing serious.’

‘So what did you do?’