Following on from what I said in the previous caption, here we see a description of what happened in the story of the solitary cyclist.

Just one problem.

I cannot for the life of me remember that story. I have a copy of the Complete Works of Sherlock Holmes (which admittedly I haven't read for years), and I was an assiduous fan of the Jeremy Brett (still the best classical Sherlock Holmes ever, so no comparison to Benedict Cumberbatch is made here) series from the 1980s (but again, I haven't watched that for ages those).

However nothing about that story as described on this poster sounds familiar. I must do some investigation; the game is afoot, Watson!