explanatory letter to Miss Gibson, in which I even mentioned the hour of our return as showing the impossibility of my keeping my engagement.  Not that I had the smallest fear of her taking offence, for it is an evidence of my respect and regard for her that I cancelled the appointment without a momentary doubt that she would approve of my action; but it was pleasant to write to her at length and to feel the intimacy of keeping her informed of the details of my life.

The case, when we came to inquire into it on the spot, turned out to be a suicide of the most transparent type; whereat both Thorndyke and I were, I think, a little disappointed—­he at having apparently done so little for a very substantial fee, and I at having no opportunity for applying my recently augmented knowledge.

“Yes,” said my colleague, as we rolled ourselves up in our rugs in adjacent corners of the railway carriage, “it has been a flat affair, and the whole thing could have been managed by the local solicitor.  But it is not a waste of time after all, for, you see, I have to do many a day’s work for which I get not a farthing of payment, nor even any recognition, so that I do not complain if I occasionally find myself receiving more payment than my actual services merit.  And as to you, I take it that you have acquired a good deal of valuable knowledge on the subject of suicide, and knowledge, as the late Lord Bacon remarked with more truth than originality, is power.”

To this I made no reply, having just lit my pipe and feeling uncommonly drowsy; and, my companion having followed my example, we smoked in silence, becoming more and more somnolent, until the train drew up in the terminus and we turned out, yawning and shivering, on to the platform.

“Bah!” exclaimed Thorndyke, drawing his rug round his shoulders; “this is a cheerless hour—­a quarter past one.  See how chilly and miserable all these poor devils of passengers look.  Shall we cab it or walk?”

“I think a sharp walk would rouse our circulation after sitting huddled up in the carriage for so long,” I answered.

“So do I,” said Thorndyke, “so let us away; hark forward! and also Tally Ho!  In fact one might go so far as to say Yoicks!  That gentleman appears to favour the strenuous life, if one may judge by the size of his sprocket-wheel.”

He pointed to a bicycle that was drawn up by the kerb in the approach—­a machine of the road-racer type, with an enormous sprocket-wheel, indicating a gear of, at least, ninety.

“Some scorcher or amateur racer, probably,” I said, “who takes the opportunity of getting a spin on the wood pavement when the streets are empty.”  I looked round to see if I could identify the owner, but the machine appeared to be, for the moment, taking care of itself.  King’s Cross is one of those districts of which the inhabitants are slow in settling down for the night, and even at a quarter past one in the morning its streets are not entirely