He stops in his tracks, looks at Charlie almost frightened, whether by the greatness of his vision or by his revealing too much to a pupil it is hard to say. But a shake of his head dispels his doubts and his pacing resumes.

“Did you know, Mr. Cooper, that there is a scholar languishing in Her Majesty’s dungeons who posits human beings have developed—evolved—from more primitive organisms? In the course of the generations, we change, according to our environment, and the habits of our lives. Thus, over time, new species form out of old ones.

“Have you seen pictures of giraffes, Mr. Cooper? No, of course not, it’s not allowed. Well, I have seen the real thing. In the African savannah, Baron Naylor at my side. They are animals, not unlike tall deer, but patterned in brown and yellow, with necks that are five or six feet long. Quite astonishing, really. Well, the theory posits that it comes from stretching: to eat the leaves in the trees. Generations of stretching. Like doing gymnastics. And each generation passes on a little of its strength. It is a slow process, of course, taking thousands of years. What, however, if we slaughter the weakest animals? The ones with the shortest necks? Those who lack the will to change? And devise a systematic programme of stretches for all the young, a programme that starts even while they are still in the cradle, so to speak? Imagine the acceleration, the speed of progress! And then transfer this to the moral theatre.” Renfrew pauses, lowers himself back into his chair, careful not to spill tea. “God is a scientist, Mr. Cooper. We are promised a Second Coming. A Republic of the Virtuous. But we have to work for it!”

Above them, the ceiling creaks and Charlie pictures the little girl, bending awkwardly over a washbasin, trying to clean her body underneath the contraption of steel and leather that keeps her safe from herself. But perhaps it is merely the old wood, shifting in the cold of the night.

When Charlie returns his attention to Renfrew, the man is watching him expectantly. It is almost as though their roles were reversed, Charlie the teacher and Renfrew the pupil, awaiting a verdict on his essay on political ethics. Another boy may have taken pleasure in the situation. For Charlie, it causes a sort of ache; proof that the world has fallen into disorder.

“Then you have travelled far?” he sidesteps the look, along with its expectation. “We saw a picture, at the Naylors’ house, of you and the baron, standing on a foreign plain. I did not recognise the landscape. Flat, open, devoid of features. With a mile-high sky.”