‘I have not, alas, had the time, in my extremely busy life as a man of commerce, to study Classical Mythology,’ said Latimer, as if this were a boast he could be proud of, ‘but I take your word for it.’

‘We will work very carefully, but as fast as we can,’ said Sir William. ‘Ten minutes from now, the tumour will be visible to us and we will sever it cleanly, so that nothing remains. Your lung will be cauterised against excessive bleeding and infection and your chest cavity sewn up. When you wake, you may feel you have suffered some bruising – as though a hard-hoofed animal might have inadvertently kicked you in the chest.’

‘A hard-hoofed animal?’ said Latimer. ‘Do you mean a horse?’

‘Not necessarily. It will cause you some pain, but we will put you into a bed and watch over you. You may take a little laudanum and then you will sleep again, confident that your tumour is gone. I foresee for you a long and prosperous life.’

‘I certainly hope so,’ said Latimer. ‘I have just bought a new house in North Parade, much larger than my former property, and I wish to enjoy some soirées there. For what is life without entertainment?’

‘Indeed,’ smiled Sir William. ‘Are you ready, then, to be entertained by the Letheon?’

Now, the two doctors were swabbing blood from Latimer’s opened chest and peering in at the expansion and contraction of the left lung. What they had expected to find was a bulbous mass, a distinct heaping up of tissue like a carbuncle, which Sir William’s lancet stood ready to slice away. But there was no such growth visible to them.

They kept swabbing and the flow of blood into the cavity slowly diminished, giving them better sight of the base of the lung, which was where Latimer had experienced pain so serious it had sometimes caused him to choke and vomit, and where they expected the tumour to be found. That it was not there puzzled them into silence. They kept looking at each other and then back into Latimer’s chest. The patient snored. The doctors swabbed and stared and swabbed and stared again.

Sir William administered more Letheon. That a patient should wake during an operation was a rare occurrence, but not unheard of. Severe pain could nullify the effects of the ether, and the screams of those who found themselves awake in the middle of a cutting were terrible to hear. Many died instantly of shock.

After a few more minutes had passed, Ross, remembering the alteration of minute things he had seen under the microscope, bent down and put his face very close to the breathing lung, willing himself to look unerringly at it, as though his eye could transform itself into the microscope’s lens. Above the operating table, the gas mantle cast a white light on the moving flesh.

Wielding a small probe, Ross explored the lung tissue and what he then perceived was that this tissue was not exactly as he knew a healthy lung should look and feel. It was, instead, infested. The infestation consisted of microscopic nodules, some as minute as a grain of caviar, some the size of a frog’s egg. They were whitish in colour, but a few were now seen as veined through with a livid purple. There were too many of them to count.