Raven tried to engage in polite conversation while he pushed the food around on his plate, but all he could think about was the fact that Sarah had married this man – and all that this entailed. By the end of the meal he felt thoroughly dyspeptic and would have excused himself and gone home but for the fact that they had not discussed the issue which had necessitated his coming here in the first place.

‘So,’ Raven said as the housekeeper cleared away the last of the dishes, ‘regarding Dr Simpson. Tell me what has happened.’

Sarah waited for the door to close.

‘It all started with a rumour.’

‘These things usually do.’

‘Originating with Professor Henderson,’ she went on.

‘Henderson. The homeopathy enthusiast. Everyone knows he has an axe to grind. Simpson has always been vocally opposed to that nonsense.’

Sarah frowned at him and he realised that he should probably let her continue without further interruption.

‘Dr Simpson performed a procedure on a woman who subsequently died. Henderson claims that her bloodstained mattress is proof that she died as a result of haemorrhage. According to him, she bled to death and the fault lies with Dr Simpson.’

Raven opened his mouth to speak but thought better of it.

‘This rumour was then given credence when Dr Matthews Duncan and Professor Miller went to interview the upholsterer about the mattress.’

‘The upholsterer?’

‘The mattress had been sent to him to be cleaned.’

‘That is very irregular,’ Raven said, now finding it impossible to hold his tongue. ‘It is most unprofessional to instigate an arbitrary investigation into another doctor’s practice.’

‘They denied that they did,’ Archie said. ‘They claim that they merely sought refuge in his shop during a downpour while waiting for the omnibus and happened onto the subject by chance.’

Raven snorted. There were multiple implausibilities to this explanation, chief of which was the notion of the two Edinburgh doctors in question clambering to the top of a crowded omnibus. In the rain.

‘Tell me about the case itself.’

‘I’ll tell you what I know,’ Sarah said. ‘Mrs Johnstone, wife of Dr Johnstone at 34 Queen Street, was to undergo a straightforward procedure. Something to do with the cervix, I think. Professor Syme had performed a similar procedure two years before. Dr Simpson maintains that there was little bleeding, that the patient did not die as a result of haemorrhage.’

‘What was the cause of death?’

‘Inflammation.’

Raven refrained from asking how she came to know these things. He knew she had a habit of listening behind doors.

‘Syme must be enjoying this,’ he ventured. ‘Has he entered the fray?’

‘Not that I’m aware of.’

‘What did the post-mortem reveal?’

‘There wasn’t one. Dr Simpson wanted to spare the husband further distress. Although I think he regrets that now.’

‘What does Dr Johnstone say about this? He must have formed an opinion.’

‘I don’t know, but I think we should ask him.’

‘We?’