‘You wonder,’ said my companion, ‘why it is that Mycroft does not use his powers for detective work. He is incapable of it.’

‘But I thought you said—!’

‘I said that he was my superior in observation and deduction. If the art of the detective began and ended in reasoning from an arm-chair, my brother would be the greatest criminal agent that ever lived. But he has no ambition and no energy. He will not even go out of his way to verify his own solutions, and would rather be considered wrong than take the trouble to prove himself right. Again and again I have taken a problem to him, and have received an explanation which has afterwards proved to be the correct one. And yet he was absolutely incapable of working out the practical points which must be gone into before a case could be laid before a judge or jury.’

‘It is not his profession, then?’

‘By no means. What is to me a means of livelihood is to him the merest hobby of a dilettante. He has an extraordinary faculty for figures, and audits the books in some of the Government departments. Mycroft lodges in Pall Mall, and he walks round the corner into Whitehall every morning and back every evening. From year’s end to year’s end he takes no other exercise, and is seen nowhere else, except only in the Diogenes Club, which is just opposite his rooms.’

‘I cannot recall the name.’

‘Very likely not. There are many men in London, you know, who, some from shyness, some from misanthropy, have no wish for the company of their fellows. Yet they are not averse to comfortable chairs and the latest periodicals. It is for the convenience of these that the Diogenes Club was started, and it now contains the most unsociable and unclubbable men in town. No member is permitted to take the least notice of any other one. Save in the Strangers’ Room, no talking is, under any circumstances, permitted, and three offences, if brought to the notice of the committee, render the talker liable to expulsion. My brother was one of the founders, and I have myself found it a very soothing atmosphere.’

We had reached Pall Mall as we talked, and were walking down it from the St James’s end. Sherlock Holmes stopped at a door some little distance from the Carlton, and, cautioning me not to speak, he led the way into the hall. Through the glass panelling I caught a glimpse of a large and luxurious room in which a considerable number of men were sitting about and reading papers, each in his own little nook. Holmes showed me into a small chamber which looked out on to Pall Mall, and then, leaving me for a minute, he came back with a companion who I knew could only be his brother.

Mycroft Holmes was a much larger and stouter man than Sherlock. His body was absolutely corpulent, but his face, though massive, had preserved something of the sharpness of expression which was so remarkable in that of his brother. His eyes, which were of a peculiarly light watery grey, seemed to always retain that far-away, introspective look which I had only observed in Sherlock’s when he was exerting his full powers.

‘I am glad to meet you, sir,’ said he, putting out a broad, fat hand, like the flipper of a seal. ‘I hear of Sherlock everywhere since you became his chronicler. By the way, Sherlock, I expected to see you round last week to consult me over that Manor House case. I thought you might be a little out of your depth.’

‘No, I solved it,’ said my friend, smiling.

‘It was Adams, of course?’

‘Yes, it was Adams.’