‘He’s in a mood because I leave again tomorrow,’ Simpson said as the door closed. ‘He’s concerned that I am travelling too often, tiring myself out.’

Raven thought that Jarvis was probably right. The professor did not seem to rest. His burgeoning practice seemed to keep him busy at all hours of the day and night despite Raven’s employment as his assistant. There were so many things that he insisted on doing himself.

As soon as they were alone, Simpson brandished a letter, waving it in front of Raven.

‘Do you know what this is, Dr Raven?’

The use of his formal title made Raven wary. He had evidently done something to provoke Simpson’s ire: not unheard of, but far from a common occurrence. Raven was not afraid of him, not like he had been of his father, but he disliked disappointing the man. His disapproval could be crushing.

‘Perhaps it is a trick question, but it looks very much like a letter to me,’ Raven answered.

Dr Simpson did not smile in response. Another bad sign.

‘It is a letter from Dr Johnstone, whose wife died under my care some time ago.’

‘What does it say?’

‘I think that you know.’

‘I would hope that he has written in support of you, to vindicate your professional character, to defend you against the egregious comments that have been made by your colleagues.’

‘That is a remarkably accurate assessment of what this letter contains. Dr Johnstone delivered it himself, apologising for the delay in supplying it, hoping that it would prove to be enough to put a definitive end to the matter. He told me he had been encouraged to write it after a visit from my assistant.’

From his tone Raven reasoned that gratitude was not about to be forthcoming.

‘Did you visit Dr Johnstone?’ the professor asked.

‘Yes, I did.’

Raven was relieved that Sarah’s name had not been mentioned.

‘I thought I had asked you to leave this matter alone. That I would deal with it in my own way.’

‘With all due respect, Dr Simpson, your own way was proving to be ineffectual.’

‘How I chose to address the issue was up to me. It is my professional reputation that is at stake.’

‘And unjustly so. I couldn’t bear to see their slanderous accusations go unchallenged.’

‘So you disregarded my wishes. I did not want a grieving man dragged into this regrettable affair.’

‘Even if that was precisely what was required to clear your name?’

Dr Simpson sighed. ‘Much as I appreciate the sentiment that spurred you into action, I cannot condone what you have done. You have interfered when I asked you not to. You have added to a grieving man’s burden.’

Raven could find nothing more to say in his own defence. If this was his offence, he was guilty of it.