"Am dining at Goldini's Restaurant, Gloucester Road, Kensington. Please come at once and join me there. Bring with you a jemmy, a dark lantern, a chi… - Arthur Conan Doyle

Well, well, my dear fellow, be it so. We have shared this same room for some years, and it would be amusing if we ended by sharing the same cell. (...)

I say, Watson,’ he whispered, ‘would you be afraid to sleep in the same room as a lunatic, a man with softening of the brain, an idiot whose mind has lost its grip?’
‘Not in the least,’ I answered in astonishment.
‘Ah, that’s lucky,’ he said, and not another word would he utter that night.

The Diogenes Club is the queerest club in London, and Mycroft one of the queerest men. He's always there from quarter to five to twenty to eight. It's six now, so if you care for a stroll this beautiful evening I shall be very happy to introduce you to two curiosities.