Dr Simpson resumed walking. ‘Do not concern yourself, Sarah. Their claims are groundless.’

‘Even so, they ought to be challenged. Perhaps Dr Johnstone would be willing to intervene. He could write a letter of support, stating the facts of the case.’

‘I have no wish to trouble the man. He has lost his wife and should not be dragged into this affair. The whole thing is unseemly. A scurrilous abomination.’

‘But—’

‘Sarah, I thank you for your concern, but I have no wish to discuss the matter further.’

As they proceeded down the High Street, past St Giles’, there was a near-continuous volley of greeting. Dr Simpson was well known, and evidently, despite the efforts of his detractors, still well regarded. Truth be told, it would be hard to miss him. He was quite distinctive in appearance and unlikely to be confused for another man. He had a large head, somewhat out of proportion with the rest of his body, and wore a narrow-brimmed hat, always pushed back, leaving the whole of his face exposed. His large nose, wide mouth and exuberant whiskers would have made him intimidating without his ready smile. He had a discernible presence, like the gravitational pull of a planet, irresistibly attracting lesser bodies into orbit around him.

But how long could such esteem last in the face of a sustained assault on his character? Sarah remained concerned and she knew that Dr Simpson was too.

‘We have one more visit to make,’ the doctor said, leading her across the road, away from a rowdy gaggle. A group of young men, bounded by several constables, was being marched towards the police office. A small crowd seemed to be trailing in their wake, intent on seeing who it was that the constables had apprehended.

They turned into Jackson’s Close, a narrow alleyway where daylight filtered through rows of laundry hanging limply from the windows on either side. Stepping over a puddle of stagnant, mucky water, they entered the crumbling edifice on the left side of the close and made their way to a door on the first floor. Their knock was answered by a worried-looking woman carrying a small, snot-nosed child.

‘Dr Simpson, thank the Lord you have returned. I fear she is no better.’

Sarah thought that the child looked perfectly well – nothing that a bath and some clean clothes would not cure – but it soon became clear that the child the mother held was not the patient they had come to see.

They were led into a small, simply furnished room. Their patient was lying in a truckle bed in front of a modest fire. She was as pale as the sheets she lay upon and her breathing consisted of short, raspy little gasps. Sarah wondered about the diagnosis. Consumption? Some form of infectious fever? There was a myriad of possibilities but naming the disease was of little consolation if nothing could be done.