“Oh, but I was! Who could have dreamed it? Though it is not entirely unprecedented.” She purses her lips, leans forward, closer to him. “Have you ever been to an asylum, Mr. Cooper? A hospital for the insane. I toured one some years ago, after my husband fell ill. These days they are constructed according to the Pentonville model. Individual cells, spread out along long, spoke-like corridors, so the inmates don’t infect each other with their Smoke. Once a week the orderlies go into each cell and scrape off the Soot, to sell it to the manufacturers of cigarettes. On the sly, of course, though the proprietors know and receive a cut. As for the inmates, some are like my husband. Others have nothing wrong with their intellectual faculties at all. They are criminals, or libertines, gentlemen who have flaunted their vice. And others yet — well, for a long time now there has existed a rumour. A whisper amongst scholars; a footnote in an article by an Oxford don. That there was a man, an inmate, down in the cellars of New Bethlem Hospital, who was just like your friend here. A freak of nature! He must have died in his cell.”

“But why was he locked away?”

“Don’t let’s be naïve, Mr. Cooper. He was that which mustn’t exist. A virtuous man without pedigree. Monstrous, impossible, a threat to the realm.”

Livia listens to all this, hovering in the corridor outside, a relay station between the two boys. She gives Thomas a nod. He saunters across, into her mother’s room, quietly but without haste; leaves the door open so she can warn him if need be. Charlie, receiving Livia’s nod, hastens to carry on.

“There is something I don’t understand, Lady Naylor. You see, Grendel used to smoke. He told Livia and Thomas: that he smoked as a child. So what happened to him?”

“Impossible to say with certainty. Some kind of metabolic corruption, I suppose. A disease, one that attacks not just the Smoke glands but the whole of the affective system. It must have destroyed large parts of it. The part that governs behaviour we call sin.”

“Then isn’t that the answer? A disease that will make us good.”

Livia hears her mother grow agitated at this.

“It would not work, Mr. Cooper. The disease is clearly noninfectious. But even if we could bottle it somehow, and pass it on at will. .” She pauses, composes herself, leans forward towards Charlie. “Let me ask you this. Do you admire Mr. Grendel?”

“No. I pity him.”

“Why?”

Charlie answers at once. “He has no choice about being good.”