In the house itself they find bedchambers and drawing rooms that have not been used for generations, their floors made monochrome by inch-deep dust. The furniture is wrapped in sheets and blankets. In some rooms it is stacked, ceiling-high, and trussed up with ropes. It gives an odd bulk to sofas, chairs, and tables, turns them into mist-moored ships: a sea of dust tranquil beneath their prows. The boys’ feet upset this peace. Leaping backwards and forwards, hopping on one foot, they write demonic dances into the rooms’ memories, for servants to puzzle over in years to come.

Then there are cellars filled with barrels and bottles, others crammed neck-high with mighty rounds of cheese; a suite of rooms in an upper wing, in which all floors are tiled in chessboard patterns and all furniture has been removed; a big brass telescope that stands in an abandoned corner study and pokes its lens through the removable pane of a narrow window, taking aim at the winter sky.

Through some unspoken agreement, they do not venture to the attic. It is understood that the attic is Charlie’s space, Charlie’s and Livia’s, and, of course, their patient’s. Thomas does not tell Charlie that he has no need to go exploring there. He has already been. He went up to the attic the very day Charlie described his discovery to him, driven by a private need. It was the early hours of the evening. Thomas hid in the shadow of a doorway while two servants, a man and a woman, were taking their turn looking after their employer, the sound of their voices travelling into the corridor if not their words. When they left at last, Thomas walked up to the door and opened it silently; stood on the threshold, looking in. The servants had left a gas lamp behind, turned very low and hung from a hook far from the bed. It had taken several minutes before Thomas’s eyes learned to distinguish man from bedding. In the meantime, he listened to the baron’s breathing, even for the most part, a little too laboured to suggest sleep. The breathing reassured Thomas. He had come there to look into his own future: the flowering of the seed that Renfrew had detected in him and not been able to dislodge. Thomas had expected the raving lunacy of London, curable only by the rope. This was another outcome of his sickness, a calmer end.

If it comes to this, it crossed his mind, I can ask Charlie.

To help me end it.