He was, as I had expected, the ward’s sole occupant. Neither myself nor Chloe, I think, really understood the measure of Selwyn’s warning about what we would find until the moment we finally set eyes on him. A morphine drip fed into one of his arms, while an intravenous tube ran from his nose and into a wheeled ventilator that looked like an antique from a medical museum. His breath was torn and ragged and horribly laboured, and those parts of his flesh that weren’t wrapped in thick layers of gauze had the appearance of charred wood.

It was a dreadful, nauseating sight, and like Selwyn I found it difficult to imagine how much pain Wallace must be in, even with the morphine. It took an effort of will to take hold of a plastic chair and pull it up next to where he lay. Chloe hung back slightly, her face chalk-white with horror.

At first I thought Wallace was unconscious. His eyes were half-lidded, and the only sign of life lay in the steady rise and fall of his chest. But as I took my seat, the chair’s plastic legs scraped against the linoleum, his eyes flickered open, and he swallowed with what I suspected was considerable effort.

‘Hurts,’ he said.

I tried to find adequate words, but couldn’t. ‘I’m sorry.’

‘S’okay.’ He coughed and grimaced. ‘Thanks. For coming.’

I reached out to put a hand on his arm, then thought better of it. ‘Is there anything I can do?’

He swallowed again. ‘No.’

‘Wallace,’ said Chloe, ‘did Casey do this to you?’

Wallace gave the tiniest, almost imperceptible nod. ‘He was angry. After you left.’ He swallowed again.

‘If this is too hard for you . . .’

‘No.’ It was clear that talking took a considerable effort, and he paused often, but he appeared determined to speak. ‘Casey made me use the . . . the remote robot. To push Jerry. Found the coin next to his body.’ He licked his lips. ‘It must have fallen . . . fallen out of his pocket. Used the robot to pick it up and bring it back. Couldn’t tell you why.’

I remembered that Chloe had told me how the other Jerry kept the half-coin in his pocket instead of round his neck. I felt something icy take a hold of me, as I realized Wallace was describing how he had murdered my predecessor.

‘Just to be clear,’ I said. ‘You took control of one of the robots and you sent it towards him when he wasn’t looking, then used it to push him to his death.’

Chloe suddenly moved from my side. I heard the sound of her shoes scraping on the linoleum as she hurried back out of the ward, the door banging loudly as she slammed through it. I kept my eyes on Wallace the whole time.

‘Casey’s idea,’ he mumbled.