If our sheer curtains were not in place, the elderly couple who lived straight across Baker Street had a direct view into our lodgings, and I’d caught them more than once peering over at us with birding glasses. His state of undress would surely provoke remark.

He ignored me, but of course Holmes cared as much for propriety as I did for knitting.

‘Holmes! If you think for one moment that either of us might be a target, aren’t you inviting danger standing in the window like that?’

‘Hmm,’ said he, nevertheless stepping back and closing the curtains. ‘For a moment, I thought you might be concerned about the neighbours.’ He flashed a quick smile at me. ‘I am sorry, dear friend. I am being perhaps too careful.’ He dropped down into a chair facing me. ‘By Jove, this heat! I have just put my eleventh case to rest this year. A couple masquerading as Japanese royalty who were actually importing adulterated opium into – Watson, I said put that box down!’

‘Holmes, this is my business.’

‘Come, Watson, you have no business. Oh, sorry, don’t take offence. It is one of the things I most treasure about you; you are almost an entirely blank page. Which means you are then free to accompany me on my cases.’

I was nettled to hear that my availability seemed to be my greatest asset. ‘What do you think is so dangerous?’ I asked, waving the box at him. ‘Have you set off some munitions expert recently?’

‘It is unlikely to be a bomb at that size, Watson. But please put it down! Locks can be rigged, you know, and even fatal.’

‘Balderdash.’

‘Spring-loaded, poison-tipped darts. Blades that pierce the eye when you look inside. Oh, yes, Watson!’

I set it down, reluctantly. ‘Are you receiving death threats, Holmes?’

He said nothing.

‘Are you?’

He cleared his throat. ‘Nothing specific. But in my line of work it is wise to take care.’ Holmes sighed. ‘I’m sorry, Watson. It was not my intention to leave you out of my recent cases. Some of them require – they happen so quickly – I must stay nimble-footed.’

Hot with anger, I stood. I had recently declined to join friends for an excursion to Bath, but in a fit of pique changed my mind that instant. ‘In any case, let me not be your anchor. I’m leaving in an hour for a holiday.’

Holmes was the picture of dismay. ‘For how long? Where? Why on earth?’

‘I have had enough of this heat. A friend invited me to Bath. Several of us are going. Cards, a great deal of swimming, dining. Nothing that you would enjoy.’

‘Bath! Cards, you say? Dear fellow, I have had to lock your chequebook away for the third time! Your gambling debts will sink you. And as for fine dining, you really might reconsider.’ He said no more but eyed my middle.